3 years ago, we travelled 10 states (AZ to WA) with a small 80's stick 5th wheel. Only one campground (Reno, NV) asked the age question. It was over the telephone. They said NO. Did not bother mentioning that I was towing with a 1971 pickup.
I've lived here (Cochise County, southwest of Tombstone, on the Mexican border) for almost 30 years. Have transitioned from an engineering professional, to a part-time school bus driver, to retired (with the usual health and layoff "incentives" along the way
). I'm concerned on what you are looking for in AZ.
If you need to find work, things are tough right now (unless you are a medical professional). If you are retired, the options are more open. There are lots of developments for the retired with lots of money. I suspect that anyone hanging out on this site would have problems with a gated, age restricted, Home Owner Association hugging development
. When my parents moved down here, they specifically ruled out buying into a 55+ restricted neighborhood.
The lower altitudes get hot in the summer. Pavement melting hot. Never cool off at night hot.
"Valley of the living inferno" runs from Phoenix down thru Tucson to Green Valley and Nogales. You have already ruled most of this out, due to the large population. The Colorado River Valley, from Yuma up to Laughlin, NV is also very hot. The lower desert (Quartzsite, Gila Bend, etc) are not very habitable in the winter.
The above places are great places to bask in the sun in the winter. We are going to a few of them next week.
I really like the climate here. The altitude is 4,800 feet. Cools off at night in the summer. The "dry heat" is easier on the body than the "sopping wet heat". It occasionally snows here. Usually melts off by mid-afternoon. Only 1 or 2 snow storms per year have any impact.
We got some major problems with smuggling (both human & drug). The Mexican drug wars are being felt on this side of the border. It gets personal when a drug chase comes thru your preschool bus route.
Some excellent suggestions presented for northern az (Flagstaff / Prescott area - also higher altitude). You get more winter - which might be a good trade-off for less 100+ degree summer days.