I feel an ambitious trip / timetable is worth it. It's not like once you go, you can never go back. You don't need to soak in everything every site has to offer on your first visit.
Years ago I visited most of Utah (skipped the Zion area for another time), then headed to the Tetons in Wyoming and ended by seeing a few highlights of Yellowstone, in only two weeks. I averaged driving about 500 miles per day, just me and a brand new sports car. This was before I bought the TT, so I was moteling it.
I know now what areas in that region I'd like to visit again, and also have a better idea of when to visit... Yellowstone mid-June was a parking lot.