When you fly into OSH, you'll pay for aircraft parking for the show (from the day you arrive to the day the show ends).
If you park in the North 40, you won't need a wristband to get to your airplane from the public access points, because you won't go through the convention grounds. If you park on the convention grounds, you'll need a wristband to access the grounds during the event hours. So park in the north 40 or in GA parking (limited space and may not be available any more), and then get wristbands for the days you're going to be going to the show itself.
On the day you depart, you "check out" and surrender your parking permit and get a refund for unused days (3 day minimum).
I'm hoping I understood your question correctly and that the answer is useful.
PS - you really should consider camping by your airplane sometime... there's a lot of "extra" fun that you miss staying in the dorms.