I could've drove the going to the sun road but instead took a Red Bus. Glad I did. Learned way more from the driver and had stops for photos that I couldn't of gotten if I were driving.
As far as a small TT and tow vehicle goes. I'd take the small MH if I were doing exstensive traveling. A B or B+ would be my choice. You can park it anywhere and if needed just put a few things away and site see. Most aren't much longer than my 2500 CC LB. Perfect for gassing up or grocery shopping. Easy to pull into site seeing spots as well.
On the other hand if I were to stay in one spot for extended periods of time like a week or longer I'd opt for a small TT and 1/2 ton truck. More livability in a small TT vs a small MH. Generally bigger tanks, shower, sleeping area and kitchen. The 1/2 ton truck will be easier to maneuver around when site seeing. Even some SUV's could handle a 21+' TT easily.