Portofino and Hard Rock both have room categories called Deluxe Queen rooms. These rooms have two queen beds plus a fold out sofa bed. Technically, they sleep 6 people.
The standard Hard Rock two queen bed room is 375 square feet. The deluxe is 500 sq ft.
At Portofino, the standard room is 450 sq ft and the deluxe is 490 sq ft.
The Royal Pacific standard rooms are only 335 sq feet and they have nothing bigger. They'll let you put 5 people in this room, but note that it has the least square footage of all the hotels.
I guess it depends on your children's ages, where they'd be comfortable sleeping, and how much you want to spend.