I attended Costume College outside LA for over 5 years, and each year there were four of us in two queen beds--usually strangers matched up by a roommate service the event offered. Everyone was neat and didn't spread out over the bedroom or bathroom. I never experienced any problems, nor did any of the other roommates.
Actually, I always thought it was more fun that way. You had instant new friends and someone to show-and-tell with every night and, possibly, share breakfast and dinner some nights.
In my experience, if someone wants to go and needs to cut down on costs to do so, they're willing to share a bed.