Do you have 12 people or can you have less people ?

I beat our room with only 3 people so less is absolutely posdible.

We completed our room with 5 people.

You can have less when I did it we only had 5

You can have less. You may get paired with other people if you pick a prime time slot. That's not always a bad thing though. We had fun with the people we were paired up with, and could not have broken out ourselves.