I'm taking notes on these responses, very good info I didn't think of. the responses on traveling thru Yellowstone especially.
I don't have anything against the campgrounds I just didn't think they would be feasible, but after some digging online, and your comments, it makes sense to try for them.
I have to get out of the "what I can do" mentality, and start thinking what "we can do". I have driven straight thru from seattle to LA and back before, seattle to Bozeman once, the last one I did was Edmonton to seattle during winter, that one was sketchy cause of 300 miles of snowy mountain passes.
maybe I should prioritize the trip for what it is ,a family reunion in Minnesota.