Most of our RV club members have managed to stay active into their 80s. Some have been doing this all of their life, some started at retirement, but coming from a long experience of outdoor activity, including tent camping, so that RVing is getting away from "roughing it." There is a lot of farm or ranch operating experience as well, in these cases.
If you've not had this sort of lifestyle, there can be a lot to learn. Living in a RV is not like living in a house, there are "taking care of the RV" chores regularly. RV travel is not like road tripping in a car or traveling in an escorted group tour, again because of the things you have to take care of yourself.
For a number of our RV club members, age 78-85 has been about the range where RVing has gotten to be too much to handle, then they start going on escorted tours with the travel club, along with a bunch of 55+ youngsters who have never RVed or camped. I've met a few folks RVing in their late 80s or early 90s, but not many, and they are often with someone younger to handle the heavier chores (e.g. my 93-year-old friend with her 85-year-old ex-rancher third husband).
If just starting, the first question to think about is "can I even get into this?" I've known some folks who tried in their late 50s, with a really nice small diesel pusher, and it lasted a little less than two years before they decided for the cost, and the amount of work, their money would be better spent cruising than RVing. If you are thinking about doing it full time, that is a huge lifestyle change.
The other, if you like it, is "how long can I do this?" The answer is "as long as you are both healthy enough for the role each has chosen." That's indeterminate, just a risk you take at any age. I know nobody, in my ten years in an RV club, who has managed to keep RVing alone after the death of a spouse. I've tried, and first two years have been able to go RVing with the club, but I find that camping out alone, and RV traveling alone, is a lot more difficult than just living alone, or traveling as part of a larger group.
Still, I've kept the RV, and while it has been idle for almost two years, plan to get it out and get it road-worthy this summer, for some road trip attempts and visits to family, and maybe I can find a camping club still active (too many deaths have put an end to the one I was in).
Ages and experience. My RVing started in the 1960s, when I was a late teen, having already tent camped for five or six years. As young adults, my wife and I tent camped, but got away from it, except for scouting leadership roles, in our mid thirties. Retiring young (58-59) with thought we would try it again, this time RVing, and we got in 4 years of road trips and group campouts before my wife got sick, three 3 more years of outings in between treatments for an incurable condition, with camping activity also curtailed so we could work on her world travel bucket list (seven cruises, two escorted tours). My RVing has essentially stopped at the age you are considering starting, but that's because it is something I find I do not want to do alone, not that it is something I can no longer do at age 71.
