Do the "perfect one" and before you leave read:
www.visitvirginiamountains.com
Go to the 1st page header, under "trails" and see the routes listed in the area of Marion,VA, & surrounding states of E. TN, WV, W. NC, S. VA, & my area-E. KY. I ride with these guys that know these routes and ride them often. A riding friend did the preliminaries so this could be listed on their local tourism website. Some of the best riding in the SE USA, guaranteed! For variety, look at routes toward home in WV, many to choose from there.
Hope the fog factor rolls the dice in your favor as a common thing on those mtn drives.