Have you checked into getting a 2 bedroom villa at WL? My family of 8 (Grandma and Grandpa, DB1, SIL, DN1 and DN2, DB2 and me) stayed in a 2 bedroom last may and it worked out great! We loved having the kitchen and washer/dryer. The villa was huge! Here's a description from my trip report:
Basically, it was a two bed, two bath apartment. You enter in the main room, which has a small kitchen and the living area with a sleeper sofa, dinning table and breakfast bar, entertainment center, and a small balcony. There was also a stackable washer/dryer in a closet off the main room, very handy to do a bit of laundry when the kids made a mess. The master suite had a king size bed, TV, its own balcony, and a whirlpool tub with a dressing area complete with a sink and vanity. It also had two small closets, one of which had a full size iron and board. The master bathroom, which also served as the main bath, had a huge shower stall, sink and vanity, and a separate toilet with a door, so someone could use that while another person used the sink. This arrangement allowed up to three people to use the bathroom while maintaining privacy. The second bedroom had two double beds, a TV, a huge walk in closet, and a full bathroom. DB1, SIL and the kids took this room. They set up the crib (Disney provided it) in the walk in closet to give DN2 his own little bedroom (it was that big!) so he and DN1 wouldnt disturb each other as they sometimes had different nap schedules. Our parents took the master suite, with DB2 and I sharing the living room. He took the couch and I had brought an inflatable mattress along, I had plenty of space on the floor and just asked for a few extra blankets and pillows from house keeping.