Let's back out to the north while we fight. We can funnel them into the narrow hall. It also gives us options to get out. The house seems to be collapsing. Fighting may not be our best option.

a fighting retreat indeed, lets push past these spiders if we can, keep moving and keep hitting

You don’t have to push past them; the door is behind Barnaby.

Could you all please make sure your current hp is in the green dot over your head? Thanks. 

Let's take this room and use it to rest?  I don't think the windows bricking up is the house collapsing. 

well let's take care of these giant spiders first and see how that goes

Kif strikes the spider opposite him, obviously hurting it badly. Ireena shoots her crossbow, but the bolt goes right between both of the spiders. You aren't sure which one she was aiming at.

Fope, you're up. 

Attack the damaged one: Attack: 18 Damage: 14

Huh. 

I think that should count as a critical hit for maximum damage.

Or in the alternative you could try again.

Trying again:Attack: 7 Damage: 17

And a miss. The giant spiders go, one at each of you.

At Kif: The spider successfully bites, with a 20! Take 11 damage, unless you make a DC 11 CON save against poison (I believe you get advantage, as a dwarf), in which case you take 8. 

At Fope: I rolled a 9; the spider's bite attack misses. 

Everybody go! Kif, roll your saving throw. 

Attack: 23 Damage: 11

You puncture its tiny head with your rapier, but somehow it is still, just barely, clinging to life.

OK, Con saves first, and I do get advantage

23  and 19

then attack the damaged one

20

if that hits 14 damage

You smash it dead!

Still waiting for Barnaby here. . .

Spiders!

Firebolt 18 to hit for 4 damage.

Edit: At the living one, of course.

That’s a hit! You singe it. Enraged, the surviving spider bite recklessly at Fope, but it misses badly. 

Ireena skewers it with a bolt, dealing 5 points of damage. 

Fope and Kif, you’re up!