We live not far from Lexington and when we had our 36' coach, we scoped out the area for 'weekend' possibilities. We found only two reasonable options:
1. Yogi Bear Jellystone RV Resort in Natural Bridge Station. It is not far from Lexington and does have sites that will accommodate your rig.
2. An RV park at the Lee-Hi Truck stop right off I-81. It has been some time since we checked it but it was basically a no frills place to stay for a night or so. At the time they seemed to be adding more sites up on a hill behind the truck stop. They were full hook up. Nothing fancy but your 36' rig would fit in there and you would be close to everything in Lexington.
There is the Lexington KOA but when we drove thru it in our car, it just seemed too tight and hilly for most larger class A's.
Hopefully someone who has more recent experience with that particular area will give you more helpful info.
'07 Country Coach Allure 470 Siskiyou Summit #31578, Cummins ISL 425; 2014 Ford F150 toad; Air Force One Toad Brake.
Glen Allen, VA; Smith Mountain Lake, VA.