If you were towing your concessions trailer (assumed it weighs over 2000 pounds) exclusively in the Midwest, I'd say you will do "okay" with a Sprinter. But you live in Colorado where I assume you will be doing a lot of mountain driving, often in unpredictable weather. Therefore I think you would be taking frequent risks. The fuel economy of a Sprinter would not be worth it to me. I would go for 2/3 the fuel economy and buy a similar size motor home built on a Ford-V10-E350 or Chevy-V8-3500 chassis. Those two chassis are built stronger with higher GVWR ratings to better handle the load with tow in mountain driving.
For reference, our rig (the one in my signature) measures 23'-8" end to end so it is not a huge rig, comparable to a View B+ in size. It is a
Phoenix Cruiser model 2350, offered on the Sprinter, E350-V10, and E450-V10 chassis. If never towing, you could order either Ford with the smaller V8 engine. The slide out is optional.