Bldg 62, 63 and 64 have elevators. Bldg 64 doesn't have much of a parking lot, so if you need that you may have to park across the street. If any of the grandparents require handicap parking, make sure they bring their hangtag along. You get free valet parking at other resorts with a handicap sticker. Also, the handicap parking at the parks is pretty close.
Bldg 63 has a great view of the green that is surrounded by water if anyone likes to watch golf.
These three buildings are on the corner near the Hospitality House and close to the bus stop.
If you need a wheelchair for any of them, just ask when you check in at OKW. They will charge a deposit to your room, but credit it when you return the chair. We got one for my mother, who is 84.