Around here, a TC would win hands down. Overhead clearance is often a limiting factor (beyond those mentioned already), and many/most TCs are lower in travel mode than a motorhome. Motorhomes tend to have rather poor turning radii (particularly class C motorhomes) and poor departure angles and sometimes quite limited ground clearance.
My impression is generally that the maneuverability and height of my class C are its biggest limiting factors, usually well before the lack of four wheel drive becomes a concern. There's not a lot of experience one way or the other to back that impression up, though.
I believe the ultimate choice for getting to out-of-the-way places is a frame backpack, a tent, and a good pair of hiking boots.
