There are plenty of options in Orlando. I have been looking for what feels like forever and finally booked this morning. There are 5 of us going in March for Spring Break and Easter. I love, love, love staying on site but the money I would need for the peak holiday rates is more than I want to spend so I had to look off site.
I ended up booking The Barefoot Suites for $600 for 7 nights, it has excellent reviews.
http://www.thebarefootsuites.com/ They have 2 bedrooms, one with a king, one with a queen and a sleeper sofa along with a kitchen.
Another hotel I found highly recommended on this site was the Comfort Suites Maingate East by Old Town.
www.comfortsuitesfl.com/ Two queen beds and a sleeper sofa along with a mini kitchen.
Homewood Suites on Marabella, two queen beds and a sleeper sofa along with a full kitchen and free breakfast.
http://homewoodsuites3.hilton.com/en/hotels/florida/homewood-suites-by-hilton-lake-buena-vista-orlando-MCOVSHW/maps-directions/index.html
Holiday Inn on 535 has KidSuites, 2 bunk beds (4 single beds) and a king along with a mini kitchen. They do charge a resort fee of $11.95/day.
http://www.hiresortlbv.com/
Buena Vista Suites on World Center Dr. has two queens, a sleeper sofa and mini kitchen.
http://www.buenavistasuites.com/
There are also seemingly endless possibilities to rent a townhouse, condo or vacation home in the area. Prices are reasonable.
Hope that helps someone. We were looking for a place with a kitchen/mini kitchen (micro & fridge) to help cut down on food costs, along with enough beds for all 5 of us. These are the places that had decent reviews and fit my criteria.