NEED HELP WITH ROUTE - US40 & US81 SPLIT IN TN

My wife and I are going for a long RV Trip (Memphis, TN > Lancaster, PA > Hershey Park, PA > Washington, DC > Virginia Beach, VA > Memphis, TN). The return trip from Virginia Beach, VA back to Memphis, TN has 2 routes:

ROUTE #1 US64 > US81 > US40
ROUTE #2 US85 > US40

QUESTION: Route #2 cuts through Great Smokey Mountains between Asheville, NC and Knoxsville, TN. Google Maps doesn't really give a good elevation picture. Has anyone taken this route ? I and kind of skeptical to take it in our Class "A".

FUNNY HISTORY: A few weeks ago my wife and I took a trip from Memphis, TN to Branson, MO via US63 > US160, which was a 2 hour roller coaster ride (lots of tight windy roads and up/down). Although, I was comfortable and cool , my wife was on the edge of her seat :ohmy: her words were "please tell me we are not taking that was back". So we took a less thrilling ride home safely.