That sounds like an awesome trip!!
I have one recommendation; Yellowstone (and some parks in Oregon, like Ft. Stevens) can have horrible misquitos and no-see-um's (like the sand fleas in Beaufort). You might want to consider bringing along one of those pop up screen rooms, similar to this (Mosquito Control - Easy PopUp Screen Room
). This way you can stay outside, enjoy your fire, and not be eaten alive.
Just spent a week at Fort Steven's and didn't bring one and it was miserable. The misquitos were huge and the biting no-see-um's were getting through my bigger TT door screen to the TT interior. Killed over two hundred, one night, and had to leave the hard door shut. Will be replacing the screen for finer made one.
However, those people who did bring their screen rooms were outside enjoying their fire and meals :(