How many sanctuaries can you designate?

In my games I rule one because the description states a previously designated sanctuary with no use of the plural with neither the articles or the noun. 

I also allow my players to use it even across planes if the sanctuary has a strong enough connection. Not a quick ceremony of dedication or a place with relics but somewhere the worship of that dirty can be felt. 

Quote from D20Crew >>

How many sanctuaries can you designate?

Quote from D20Crew >>

How many sanctuaries can you designate?

 seems like only one at a time.

Does this spell work interplanar? 

Quote from Stonebraker >>

Does this spell work interplanar? 

 Since it doesn't specifically mention that it has to be on the same plane of existence (like similar spells would), I assume so and would rule so in my own games.

Is an unconscious party member a willing creature?

I would say no because they do not currently have the ability to choose to go along with whatever is happening around them.

Quote from LokiLockdown >>

I would say no because they do not currently have the ability to choose to go along with whatever is happening around them.

 No, an unconscious person can not be considered willing (or unwilling for that matter)

Under sage advice JC considered spells requiring willingness, to use the will of that creature in the magic of the spell. The same I assume is the case on unwillingness, the resistance of the spell would be an element of said spell.

I want to make sure I am understanding this right. It takes two casts to actually use, correct?

First casting to set your destination and then the second casting later on to actually teleport to your destination?

Can you cast it at a higher level to take more people? A lot of teleport spells allow that, but this one does not specify what happens if you cast it at a higher level. 

As always, it is up to you, the DM, to decide how things work in your campaign. I would say only one sanctuary at a time. If you designate a new sanctuary, then the previous one would no longer be a target for the teleportation action.

The wording states "a sanctuary". Also, I think designating multiple and choosing at time of teleportation seems a little OP for a cleric. It takes only an action. Wizards have to cast for at least a minute.

I think the idea is that your diety is providing you a refuge, a sanctuary if you will, when you most need it.

it's a fun spell to combo with the 7th level spell temple of the gods, i did that recently where i placed a temple not too far from what we thought would be a hard boss fight and i had it available to word of recall us to if the fight went south.

Well I wouldn't consider it UNwilling

Quote from Norvos >>

I want to make sure I am understanding this right. It takes two casts to actually use, correct?

First casting to set your destination and then the second casting later on to actually teleport to your destination?

Yeah

Quote from Davros333 >>

Can you cast it at a higher level to take more people? A lot of teleport spells allow that, but this one does not specify what happens if you cast it at a higher level. 

As a general rule, spells do what they say they do.  Since this spell does not define additional effects from upcasting, there are none.

.

Quote from DM_Duncan >>

Is an unconscious party member a willing creature?

 I would see an uncounscious person as "baggage" basically. so as long as they are carried...

TL;DR
DM consultation is highly recommended. The spell doesn't say that you get to designate the creatures. That can go sideways real fast if your DM hates you. Spell also pairs well with many charm spells.

FAQ

• The ability to designate only one or many sanctuaries depends on how your DM interprets, "the spot you designated when you prepared your sanctuary." It sounds singular, but it's "your salad" even if you have many salads.
• No additional benefit for casting at higher levels.
• Must be willing creatures. Unconscious creatures are not willing. "Not unwilling" doesn't satisfy the condition.
  • Do people arrive naked or do they take what they're carrying?
  • What if a willing person carries an unconscious person? The creature that is willing goes, the creature that is not willing doesn't. Downgrading a creature to an object to slip through rules would probably break a bunch of mechanics. Now if you want to pop them into a portable hole for a minute during transit...

Gray Area

• Warning! It is NOT restricted to creatures that you designate!
  • I feel that the clause should be "5 willing creatures [that you designate]" for a 7th level spell, but I don't know. Because otherwise...
  • What if you have 3 allies and 5 enemies around you, and everyone wants to (willingly) follow you to a) escape with you or b) attack you? Who comes along for the ride?
    • Only the 3 allies?
    • The 3 allies and 2 enemies?
    • Possibly only the 5 enemies?!
    • The 5 highest, I don't know, Charisma rolls?
    • Key factor: is the "up to 5 creatures" there to:
      • clarify that the spell isn't wasted if there are fewer than 5, since there are other spells where the spell is wasted, or "cast with no effect"? Or,
      • imply that you get to designate the creatures, up to a maximum of 5?

Imagine
You're trying to get your party out of the abyss. You're all huddled up and demons are upon you. You cast Word of Recall to retreat to your temple (of the gods) with your companions in tow... but instead they get left behind in the abyss (now without their cleric) while 5 demons just got a free pass into your otherwise-protected temple where they now run amok.

Conclusion
So yeah, definitely want to find out how your DM interprets this spell beforehand.

Also, this could be the basis of an adventure where House Orien is partnering with a temple of the Sovereign Host, especially if one cleric can collect many points of recall via a pilgrimage. Or perhaps it is a corrupt cardinal of the Silver Flame looking to broker his services for hire.