I went down the BRP about 300 miles 2 weeks ago, and it was a pleasant experience......until we got into fog on the 2nd day. That is the only reason we didn't do the entire length.
Mind you, we were towing a 28.5' foot bumper pull trailer with a super cab pickup......about 50' total length. I think a MH would be OK, but an not sure. The devastating snows over last winter have left plenty of tree limbs beside the road, and overhanging tree limbs could be a problem.....several times I had to go over the center line to save my awning from brushing the trees. We went through several tunnels without a problem........my trailer tops out at 9'10".........but there was plenty of room left over.
A big problem with the Parkway is where to get on and off. Many of the access roads are step and narrow. I highly advise getting the Eastern Mountain Directory (http://www.amazon.com/Mountain-Direc...5680234&sr=1-1
). Since you appear to already be underway, you might find a copy at a truck stop. We used that many times on our trip. Some roads off on and off the parkway don't advise vehicles over 35'. Some list grades of up to 10% Also, it lists the major grade changes on the Parkway.....I think the most was about 8%.
If you are comfortable driving your MH and want to see some beautiful country, do it. But like Richard advised, call the National Park Service and get the details.
Chap , DW Joy, and Fur Baby Sango
2006 Ford F150 Super Cab 4x4
2008 Surveyor 263