In 2008 my wife and I drove the Parkway and Skyline drive. We guessed about two weeks for the trip. It took us 7 weeks. We found the drive to be very interesting. I had been on the same drive back in the 50's. The biggest change was that the trees had grown and the view was not as majestic at all of the turn-outs like I had remembered. The camp grounds are a little tight and many are for small trailers and tents.
Saying all that we would and plan on going back again. There is so much to see and do...a great place to relax and meet a lot of nice folks.
We drive a class C and pull a car....we are 12 feet high and 54 feet long....we had no trouble on the road.