Before we got into RVing, we did this 3 or 4 times. The kids ranged from 4 to 9 at the time. The trips were exactly as you described, with two exceptions. I would rent an unlimited mileage, fairly large sedan, or medium sized SUV to rack the miles up on, and we started out trips from northeastern PA. Honestly, with two drivers, it's no big deal to blast out to Yellowstone in two days from your location. Personally, there is no way that I would pass the Black Hills, or Cody, WY. without spending a few days in each, but that's what I enjoy. Have a great trip.
