What we usually do is call the campground at Roan Mt. and ask if they have any sites available and if so how many, they can also let you know if sites will be available later in the day. It takes about 20-30 to drive so if they have a couple of sites open, then we take a chance on getting there. We have always found a site, but I've never been around holidays. We figured if they were full when we got there, we'd just drive to NC or somewhere else close by, we're kinda spontaneous.

Last fall we went up there and we had one whole loop by ourselves.

Also the bottom loop is almost always full, but we don't mind being "up on the hill". Most of the sites can fit any size camper, ours is only 8' so we can squeeze in almost anywhere.