The tunnels for the most part are short in length and you can see car's coming from the other side. I would have no trouble with moving to the center and use the middle high arch if you think it isn't going to fit.
With the low speed limit the on-coming cars will stop and wait on you to clear the tunnels... I only recall a couple of them that was questionable as compared to the others...
The major pull-outs are well designed to accept the longer trailers...
I do however like the idea of parking the big rig somewhere and driving the tow vehicle.
Also note there is a limited number of FUEL STATIONS along the parkway usually at the way-stations. Might be only three of them as I recall for the whole distance... The problem will be if you do not use the major road entrance places you can really get into trouble big time with very steep hills and winding loop-back roads with your big rig. I would make a point to never take any small road off of the parkway to head for a small town to get fuel...
Back in the day I have driven the entire 460miles length I think it is and TENT camped at all of the camp sites which are along the parkway about every 50 miles. The camping areas were originally designed for tent campers.
My OFF-ROAD POPUP trailer of course does just fine and I see Motorhomes and 5th Wheel trailers using them...
Also note none of the camping locations has any hookups. They do have central rest rooms with available water from a spiqot... Most always had firewood available at the sites...
Driving the BLUE RIDGE in the dusk and early evening you really have to watch for wildlife crossing the roadway.. Plenty of Deer everwhere... Always remember it isn't the one you usually see running across - its the 5-10 or so behind that one you have to worry about. They are playing "follow the leader"...
CELL PHONE service will be spotty and alot of time when we was camping at the camp grounds we found NO cell phone service. Had to drive back to one of the pull-outs places to get VERIZON signals...
You can also always check the various road conditions by contacting the BLUE RIDGE main site which I was posted here in another thread... They do close down sections for bad weather...
Roy Ken