We camp there at least once a year, State Park that is. We usually camp there in the fall, and "boon dock" so early reservations aren't needed.  One note, The State Park has only one loop with electric hook ups, they usually are booked a year in advance for the summer.

I camp at Assateague Island National Seashore several times a year.  It is one of my favorite campgrounds.  I think the "best" time to camp there is in the fall.  The mosquitoes and green headed flies are gone or mostly gone.  You need to book well in advance for the summer season.  We do go there each summer.  If it is dry the bugs are not too bad.  If it is wet the bugs are awful.  I have pictures of the national park on my webshots albums.  I am going the end of June this summer.  The national park does not have any hookups, chemical toilets, and cold water showers.  The cold water showers feel good in the summer.  The water is slightly warmed from the water lines running through the sand.  Horses and sika (small asian elk)are all over the island and will come visit.  You are not allowed to touch any of the wildlife including the horses.  🙂

Joe
I'm in for a group camping if there is one. Fall sounds like a great time.