When heading for the gap, I usually leave Cbus early and have lunch a little north of Knoxville. I am riding the tail of the dragon in the early afternoon. Granted, I ride a touring bike. If, as you say, you can get comfortable on the freeway, make the trip on the bike. It really isn't that hard. Just take an ibuprofen or two and wear some biker shorts. It will make the campfire beer that evening taste much better. It was that trip that sold me on the benefits of sport touring bikes.