There are also plenty of Disney Vacation Club villas that you can book directly with Disney as a cash stay. A one bedroom villa at the Animal Kingdom Lodge (Kidani) sleeps 5 (but we did it 2 years ago with just 4 of us, and the living room was impossible to navigate with the sofa sleeper and sleeper chair opened, so I wouldn't do that again, but my oldest joined us last minute). It did have 2 bathrooms though. I love that it has a washer/dryer and full kitchen.
Some studios sleep 5, but that's just too many in one room for me.
There are 2 bedroom villas also, with full kitchens and washer/dryer. Of course they cost more, but would give lots of room.
Rentals may save money, on sites like redweek and David's Disney rentals. Often, there are general discounts, though (I have one booked in May, and with the discount being offered, it's costing the same as renting from David's, plus I get daily maid service paying cash, and have the flexibility if I need to cancel).