Hey, I know where Brrrrrmidji is, I have a brother that lives just west of there out in the boonies.
You have a pretty tight schedule if you only plan on 250-300 miles/day. Try to do the Beartooth highway out of Red Lodge, MT. And Chief Joseph Highway if you have time. Farther west, there is just too much to see to narrow it down, perhaps someone local can help you on that.