Due to some employment issues I will need to postpone my Fall roadtrip until the Winter (December'ish). I had hoped to do a lot of camping and visit Yellowstone and part of Glacier. My guess is that those plans will need to be scrapped, and even the Tetons and Mt. Rushmore are looking doubtful in December. Ugh. This is disappointing.

I can take a more southern route, and no doubt there's plenty to see down there, but I'm feeling robbed right now.

Any comments on places I should/should not consider in the winter? Do I need to avoid most of MT,WY,CO,SD,ND? I have a RWD car with snow tires, but obviously would prefer not to drive on unfamiliar snow-covered roads.