I've only stayed in the POP rooms. The rooms with double beds are tight if you have 3 or 4 people, but functional. It's not something where you can turn a wheelchair around wherever you want, but you can move past a wheelchair fine. There are a lot of nooks and crannies to store luggage so that there is more space for the wheelchair to move around. I would consider it cozy, but not degrading by any means.
As a PP mentioned, there are connecting HC rooms with a king bed to a standard room with double beds. We requested this our first year and arrived to find that they had assigned our room to someone else and told us we were SOL for our entire trip...so I wouldn't count on getting a HC room necessarily.