For a large class A, the southern portion of the BRP is not at all friendly. I have been on all of the parkway from Ashville south to Cherokee at the southern end and most of the parkway north of Ashville up to Linville Falls.
The two or three of the tunnels south of Ashville (actually those from US 19 to the south end, are the lowest, and while tall in the middle the height at the edge lines are not great, combined with the fact that the tunnels are not straight and you cannot see from one end to the other.
Tunnels - Blue Ridge Parkway
The first nine tunnels on the list are north of Ashville and the remainder are south of Ashville.
The roadbed of the BRP is only 20 ft wide (10 ft lanes) vs the standard 24 ft roads found most places and while many of the pull offs are large, they can get rather packed in the busy season, making pulling off in a large Class A difficult. Also, there is not real suitable camping on the parkway for large Class A's, with the possible exception of
Julian Price Campground
I would encourage you to pick locations near the parkway and use the toad to drive sections of it and then leapfrog up the countryside. Where the parkway ends on the north end at I-64, the Shenandoah Skyline Dr continues for another 100 miles to Front Royal, VA at I-66.
To me, the most scenic section of the BRP that I have seen is the southern section, largely due to the elevation.
If you have not been to Biltmore (and I have not yet) this would be a good time to, as the parkway passes very close to it. Also the
The North Carolina Arboretum, is adjacent to the parkway (we spent an afternoon there) and its entrance is adjacent to one of the BRP interchanges, right at the French Broad River in Ashville, again, very close to Biltmore.
Crabtree Falls, Linville Falls from well above it, view from Mile High Campground just off the parkway, Highest point pull off, Mingo Falls at Cherokee, Soco Falls on US19 near the parkway interchange. (both Soco falls and Mingo falls are on Cherokee tribal land), last two self explanatory.
Charles