We have a room for DH, DD, 9yr. old neice, and myself for our upcoming Poly trip. 20 yr. old son is saying he'd like to fly down to stay a night or two. Can 5 stay in a Poly room legally, with my neice on the daybed and DS on an aerobed? I'm leaning toward getting him a cheap room offsite, but not happy about that, either. Not worried about the comfort factor, just the rules for Poly rooms.