Hi Stephanie,
We're right there with you. No one in our family wants to share a bed with my younger daughter, who is a kicker and a flopper. Now that she's 5'8", it's really a problem.
On several occasions, we have gotten a rollaway bed when we were at a value resort such as Pop Century or one of the All-Star resorts. But it's a pretty tight fit in the room. And availability of rollaways is sometimes limited. There is an extra charge of about $15 a night for the rollaway.
I'm not sure how old your children are, but if they are still relatively small, you might want to look at
Port Orleans Riverside, which has a pull-down bunk for one person in many of its rooms. The bunk may not be big enough for an adult-sized person, however. You also can request a rollaway in the moderate resorts.
The most comfortable option for our family from the time my daughters reached their teens has been a deluxe resort, where rooms all have a sofa that makes an extra bed, which cuts down significantly on the discomfort and the complaining. I slept on the extra bed at the Contemporary last year during a girls weekend and found it very comfortable.
I hope that helps as you search for the best resort. Please let me know if I can answer any other questions for you. Enjoy!
Wilma