Just returned from an amazing two week trek through ten states to spend some time in Yellowstone.
First, the TM (2006 2619) was an absolute ace on the trip. No operational issues, and slept like babies every night. Got questions and commentary as we would set up or take down (or even gas up the Jeep). Even saw one person explaining how the TM worked to another member of their party as we eased into a campground. This trip is the reason we purchased the TM in the first place. That was one of those decisions you look back at and say, "Oh yeah, good move!"
The campground we chose as a base from which to tour Yellowstone was the Rocky Mountain RV Park in Gardiner, MT.
http://www.rockymountainrvpark.com/index.htm
It turned out to be precisely the choice for the manner we wanted to see Yellowstone. We wanted to camp as close as possible, and to make daily road trips into the park for specific destinations each day. Since the campground is only blocks from the historic entrance, that was easily done.
Facilities were very good. Sites were level and clean, with the occasional Elk leaving a calling card (which after all is a bit of the park/mountain ambiance isn't it).
Actually, with the small cabins available at the facility, one could fly any "non-camping" family members out to see the park as well. That's an aspect we will consider on our next trip.
Staff members were very helpful, and willing to help "design" the best trips to see Yellowstone.
Between the TM itself, the many vistas and great places to see along the way, and the majesty of Yellowstone, this trip was one of the great experiences of our lives.
Camping your way through only puts you in the middle of it all. There were others worthy of mention on the route that I will add as I review my notes ...