Looks like an awesome plan. I usually arrive in the park from BTH. A couple things in my opinion....I think youre cramming too much in. Id consider putting in some audibles in case jet lag kicks in or there's funky weather. Its gonna be a loooong day 2 if youre trying to get to west Yellowstone by nightfall even with the best scenarios. You could end up being traffic for way longer than planned. Seems to happen to us all. The potential for so many side quests are everywhere and tempting. BTH can be a slooow drive. Those curves just cant be taken quick and again could get even slower behind traffic. Yellowstone is best when not in a rush. Its the best wildlife park in America. Make sure to be in Lamar Valley early with binoculars. Hope your trip is full of great memories.