I have a 60 X 80 hangar, and four planes fit easily, and six would work with
a lot of juggling. The risk for hangar rash goes up a lot and it becomes a
big pain to get your plane out, particularly if it is one of the inside
ones, especially if it's raining or snowing outside.

Also, you have to have a lot of trust in the other owners so they'll be as
careful with your plane as you would, and be sure that everyone has
insurance.