We were just at OKW this past week. As you can see in my signature that we are campers as well. This trip we had some free plane tickets, so we flew down and rented a car. From what I saw after driving around, parking is at a premium at OKW, and I would not want to park our 38' MH there... its just too tight. I did not see any "open" parking areas (you know the areas where you can pull through and take up two spaces). The other thing you will have to look out for is the trees and limbs. The main roadways are open so that the buses can manuever, but there are alot of limbs that overhang the parking spots.
If I were a betting man, I would say that you will have to park in the overflow lot at FW, or make some arrangements to park in POFQ, or Riverside where the lot is larger.
There's nothing like riding in your "living room" on the way down or back from Disney!!