We stayed at the Marriott Grande Vista in November. It was myself, my DH, and DS - age 6. The grandparents and sister/brother in law were also there part of the time. We had a 2 BR lockout unit. The second bedroom was like a little apartment. It had a small microwave, small refrig, sink area with dishes, coffee maker, small table, separate entrance, small table/chair and balcony. It also has a sleeper sofa and a regular bathroom with tub/shower. I would think the grandparents would like having the separate small studio unit. Of course, you may wish to stay in this studio room and give the grandparents the master. Your children could easily sleep on the sleeper sofa in the studio (second bedroom) and the parents could have the bed (it was a king size bed). Oh, there are also safes in each bedroom. The master bedroom has a nice jacuzzi tub.
The living area has a sleeper couch. Lots of room. And of course, a washer/dryer is a blessing with small kids.
We stayed in a unit near the main pool that was on the golf course. We enjoyed having breakfast on the balcony while watching the golfers. We even saw a space rocket launch there one morning. We also were able to see the fireworks at Sea World from the front landing/balcony.
MGV is very close to Sea World and an easy drive to Disney. The resort is nice. They have a really cool indoor climbing play area for the little kids. It was raining the first day we arrived. My DS LOVED playing on the climber and it helped to unwind him for the long travel day. They also have small boats you can rent to go out on the "lake".
If you have any more questions, let me know.
