East Fork of the San Juan River near Pagosa Springs this summer showed me graphically the pros/cons of the various RV types. The road goes from pavement to 4x4 over a few miles.
Down low were the Class As and large Class Cs.
Further up the 24 foot Class C's like me had to stop because of gullies without culverts that presented too much approach and departure angle. I rode my dirt bike (carried on a hitch rack so I can back the RV up) and mountain bike from this point forward. Meanwhile I had the amenities of a C.
TC's may be able to get all the way over Elwood Pass, but it is very rough for anything but small 4x4s and my dirt bike. I would think bedrock steps are a bit much for a TC.
And the RV's furthest up? Sizable TTs and toy haulers pulled by big 4X4 pickups. Some of the most palatial were WAY up the valley past fords and serious gullies.
I like the ability to stealth camp in my C, but I have to give the TTs / TH's a nod for their terrain versatility.