A couple generic comments:
Did a round the country trip in 2011-2012 and that area was a highlight.
Your TOTAL mileage may not be that far off, in fact a little low. We found that we would drive about double the distance in our toad, compared to that covered by the RV. The RV moved once a week or so, the toad, every day.
I love to fly. Breathing the air-not so much. Taking only what you can carry, renting cars, hotel rooms with who-knows-what on the floors and showers-yuck, yuck and yuck. That works for funerals and maybe a wedding. Vacations? Exclusively RV.