I must have too much time on my hands. Just out of idle curiosity, I searched for 2 adults 3 kids for next March. Offers standard room and preferred room, both of which say hold 4 adults. And 5th sleeper rooms at both CBR and POR not available. So then I had chat sessions with 2 CMs. Second CM said something about Disney changing names of room types and can't book a 5th sleeper room in 2026. I said confusing and not helpful. My best guess is parties of 5 will get dibs on 5th sleeper rooms when checking in. How a party of 3 or 4 will get a 5th sleeper room, I don't know. Guess you could put in a request either before arrival or on arrival.