And when compared to air travel and hotel stays (which come with large water and heat costs associated with daily laundry) it's actually less of a carbon footprint.
The average 2017 car in the US got 25mpg. So with a 15+mpg difference, you'd need to either drive 5 miles or less per day (0.3g difference), OR average 100 miles per day and have the hotels wash the laundry 20x as much.
Also, retirees roaming around the country in an RV generally sit in one place for a week or two at a time.
Some people literally live in hotels.
Otherwise the argument becomes "Staying at home is better for the environment than traveling", which is true, not not really a fair comparison.
https://yaleclimateconnections.org/2015/09/evolving-climate-...
"In addition, Sivak suggests carpooling, as having three or more person in a vehicle “completely” changes the comparison with flying. Indeed, with a few people in the car, “driving becomes less energy intensive than flying (even after taking into account the increased weight that the vehicle needs to carry).”"
Edited to add quotes.
The laundry footprint is a large factor when considering hotel stays. If we add up both the carbon costs of the hotel stay and airfare added together it seems like it adds up to more than the RV option. That's all I was trying to highlight, I haven't done a research paper on it, just my perception.