POR in the alligator bayou section is the only place you can have 5 in one room in any value or moderates(unless one of those 5 is a child under 3). They have 2 doubles and a trundle bed that rolls under one of the doubles. It won't exactly be roomy, but we were fine there with 2 adults and 4 kids (10,7,4,1) and would be happy to stay there again.
The trundle bed is supposed to accomodate a child under 10. I can't personally comment on it because our room was missing the trundle bed. We called the front desk and they brought a rollaway bed instead. Maybe they had a shortage of trundles, I don't know.
I think most of the deluxes can accomodate 5 people in their regular rooms. But I thought at AKL and WL, the standard rooms could only have 4 and you had to get a deluxe room to have 5 people. I'm not positive though.