WyoWoman--I just sent you a PM, hopefully giving you reasonably good directions to Gary T's camp and ours. You might want to holler at Gary; he may be able to be more precise.
If you're planning on buying a ticket that includes camping for a night, they should let you into the campground with your car, no problem. Ask them at the gate how to get to the Pecan Grove, and go from there. As I mentioned in the PM, though, you'll probably have to take your car back around once you've unloaded, as parking in the campground is at a premium, and by Friday night may be impossible.
The sooner you can get there, the better, of course. And sleep? At Winfield? Only if we get flooded out!
Lin