If you are a guest in a cabin, every vehicle is charged for every night it is at Fort Wilderness, no matter where it is parked.
If you are a guest at a campsite, no vehicles are charged for overnight parking at the campsite, although there may be a limit on the total number of vehicles per reservation.
It also matters if you are a guest at Fort Wilderness at all. A person not staying at Fort Wilderness would be able to park for free there to go to an ADR or visit the campground IF big IF, they are allowing non -guests to park there. At really busy times, they don’t allow any non-guests to park there.