The Virginia Creeper Trail is lovely, but I would not attempt it on a road bike. My husband has ridden the entire thing, and I've ridden a good portion of it, and he tells me that none of it is paved. We rode part of it one year on our Bike Fridays (which have 1.35" wide tires), and I said "never again". My hands got super tired from clutching the road brakes from the hoods so much, and the surface was not good in places -- washed out, muddy, rocky, sandy, so I wished for suspension and wider tires. I actually preferred riding back uphill to the downhill direction since my hands got so tired from braking.

Fast forward to a couple of years later, and we rode more of the trail on our full-suspension mountain bikes. That was a blast. The MTBs handled everything it had to offer in terms of terrain, and the brakes were much easier to apply in the downhill direction.

I would not recommend it on anything but mountain bikes, personally, but it will depend on what weather conditions have been like up to that point. The more rain, the more washed out certain sections will become.

We do love our Bike Fridays! Sounds like your friends are having fun. We have done some touring on them but mostly use them for utilitarian rides with racks and panniers/trunk bags and for travel.

I had forgotten about the RR grade road. I have heard of it but never ridden it. Sounds like a good option to check out for a road ride!