Neldak hesitates in casting another spell as she promises a chest of gold.  He considers what happened to the poor fishermen as he watches Danon continue the attack.  He'll hold off an attack for the moment.

I'm not going to roll a save. Each of those three attacks individually would kill her. (she would have honoured her word. But also you would be letting a powerful murderer walk free. I'd have done the same)

The hag falls down dead, the light from the willowisp fading as she does, it's soul no longer tied in servitude. 

[Danon you're not injured, correct? if you are I will heal you]

Danon is unscathed from the encounter, as he sees her fall to the ground he gathers himself up, straightening his cloak and taking some deep breaths, the air exhaled forms a fog that floats to the ceiling.  He seems to be calming himself down from the swift, sudden violence that ended her life.  He looks over to the filleted fishermen on the table, bowing his head.  “I’m sorry we were too late… too late to save you.”  He turns to look at everyone, looking them over.  “Everyone okay?  I’m sorry if I acted rashly, ended her instead of further discussion of that she was promising.  I would not trust that hag at all, she would try to kill us as soon as she could.”  

"Probably for the best, Danon.  She won't harm anyone else."  Neldak will attempt to hide his hesitation.  "We should probably bury them here.  I don't think anyone wants to see what happened to them." Neldak will look around for some personal items from the fishermen and eventually end up by the cauldron, curious about if the hag was telling the truth about its magical nature.

The fishermen only planned on heading out for a days fishing so most of their belongings were probably left at home and they don't have much. That being said, you find two wedding rings, but the other two have nothing on them.

The cauldron has a stew in it. But also floating in the stew is lumps of flesh and organs, presumably from the fishermen. The cauldron does carry some aura about it that almost resonates when you touch it 

"We can at least bring these back as proof we found what happened to them." Neldak will retrieve the rings.  "That cauldron will need quite a bit of washing before I'd eat anything from it."  If the others aren't in a hurry to leave, Neldak will ritual cast Identify on the cauldron.

Etriel Darastrix approached and exhales a quiet sigh of relief at seeing how the incredible elf who made his own body a deadly weapon managed to elude the hag's terrible assault: "It seems that once again the combined skills of martial arts and magical arts have prevailed over brute force and overwhelming ugliness. The fact that you managed to prevent that witch from attacking others and that you did not suffer a single scratch, sings your praises by itself, sweet guest of my soul".

The foreign traveler disagrees with the proposal to bury the victims here: "I do not know, Lord Neldak... As horrible as the treatment inflicted on the victims was, I expect that their families would prefer that their loved ones be buried in a place where they can easily reach them to pray for them - or even simply to feel a little close to them thanks to the power of memory".

While waiting for others to speak, the eladrin huntress instinctively calls to mind and lips gestures and words derived from the magical traditions of her people and tries to examine the aura of the Cauldron that her enemy, before dying, had defined as 'magical'.

The cauldron displays an aura of conjuration magic. And after Neldak's ritual it's a cauldron of plenty. Moving it will be challenging but not impossible. 

"In these lands where food is not always easy to find, this item can be very useful..." Etriel Darastrix muses aloud "In any village, once a few people are taught to use it, it is easy to produce 90 gallons of stew a day. It can mean the difference between satiety and starvation - if not life and death - for many people."

"Having it routinely, for those of us who travel frequently, would not be practical," the foreign traveler assesses. "But if we left it in the nearby village of Easthaven, we could ask for payments or favors in exchange - perhaps favorable trade agreements for Good Mead. Everyone would benefit... Good Mead for the agreements and Easthaven for the food."

"And if we made a deal with Easthaven," the eladrin huntress concludes, "we could certainly gain their assistance in transporting this item first. They could provide us with a wagon and some porters - and then even this heavy treasure could reach its destination without difficulty."

"I wonder if the same food over and over gets old.  Sounds like you've got it all planned out Etriel. Shall we head back?"

"Personally, while we're here, I'd like to take a look at the room with the other giants imprisoned in the ice..." Etriel Darastrix suggests "Perhaps, as in the case of our previous exploration at the forgotten Silvanus' shrine, this will shed light on some peculiarities of this place..."

"I would lean towards returning the bodies also. Let their families decide what's next for them. Looking at those giants while you still have your detect magic sounds like a good idea, perhaps we'll get lucky and find some magic trinket!"

Cirim will then begin a prayer to her goddess for the fallen fisher folk.

There is nothing further at the pool location. It seems to be the area which was shown in the cave drawings (in other words, the giants seem to have willingly entered, at a time before the lake froze). Judging by their varied states of decomposition, they didn't all enter the pond at the same time. There is nothing to suggest why they did it though.

And with that, unless you feel like attacking the lone wolf in the front cave, I believe this "dungeon" is complete (with the exception of logistics for the cauldron)

Etriel Darastrix is ​​not very satisfied by not having revealed the mystery of the madness of the giants, but she finds consolation in drawing. She first draws a map of the complex. Then, on the back, he reproduces both the 'current situation' of the giants, who now has under his eyes ... and the 'past situation', the cave drawings (moving to go and see them while copying them).

Finally, satisfied with its work of art (and cartography), Foreign Traveler is ready to leave the dungeon. As for the logistics of the cauldron, if the party agrees to leave it in Easthaven in exchange for a counterpart, it will probably be the authorities of Easthaven herself to lend a chariot to the party and some porters for transport.

"As far as the cauldron, I can cast Enhance Ability to make someone a bit stronger if we think it could help in carrying it?"

"I can help carry the cauldron.  It will probably slow us down a little. But surely a few of us can carry it between us."

Danon is fascinated by the cave drawings as well, he watches as Etriel draws her map, then makes a copy of the drawings.  He helps the others to dump the contents of the cauldron, then says “A lot to carry.  I’ll certainly help.  Are we carrying the bodies too?  This cauldron will certainly help in our alliance with Easthaven..”

Etriel Darastrix had imagined returning to Easthaven quickly and without too much encumbrance - therefore without the bodies and without the cauldron - and then negotiating and borrowing a wagon and porters to facilitate the transport.

But if the party can organize the transport of everything right away, the foreign traveler has nothing to object. Unfortunately, although stronger than most elves, she is certainly not the most useful element, for simple transport tasks. She tries her part, but probably can't do much more than (with difficulty) carry a body or help carry the Cauldron.

You can probably get away with loading the bodies and cauldron onto one of the two boats, and sliding them across the ice following the coast. It will be hard work but doable