I normally ride like the OP asked, stop for gas and quick bite, site see from my saddle. I rode from Pittsburgh to southern end of Skyline (Skyline was closed at the time I think it was a National Park budget thing can't remember) by Waynesboro then down BRP to Boone in one day, but arrived pretty late in Boone, around midnight just shy of 600 mi. I think this would be similar to going from Front Roya to Asheville. Spent a few hours riding along BRP at night, wasn't a good plan, saw a lot of deer on road and it was pitch black. Be careful of dusk and dawn with the animals. Its a long day with all the sweepers. I 'd skip Skyline, its boring compared to rest of ride.