We have stayed in Las Cruces for 4-6 weeks in winter. It's great for 1-3 day toad trips to Big Bend NP, Carlsbad Caverns and Guadelupe Mtns NPs, White Sands NP, Organ Mountains NM, Gila Cliff Dwellings NM/Silver City, City of Rocks and Rockhound State Parks, White Sands Missle Range, Cloudcroft/Sunspot (National Solar Observatory), to name just a few!
We have also snowbirded in Tucson for a month or more. There are not as many national parks within easy driving distance, but several national monuments. But Tucson is a much larger city than Las Cruces and has more to do in, and right around, town. It has the must-see Pima Air and Space Museum and Boneyard tour, just for starters! Also, Saguaro NP (two locations--East and West), Tucson Mountain Park/Sonoran Desert Museum (with its not-to-miss raptor show), Catalina State Park, and Mission San Xavier del Bac. A little farther afield are Tumacacori National Historic Park, Tubac, Kartchner Caverns SP, Tombstone, Bisbee, Organ Pipe Cactus NM, and Chiricahua NM/Fort Bowie NHS. And there is major league spring training 100 miles away in Phoenix.
We have primaily stayed at Rincon Country West RV Resort in Tucson. Nice outdoor pool, big auditorium/theater for events and entertainers, 3 laundry buildings, dozens of clubs, workout room, library room, meeting rooms, craft rooms, wood shop, lapidary shop, and outdoor model train layout. Also, a dog park, pickleball courts, shuffleboard, and a bike path right out the back gate that runs along the Santa Cruz River for miles. BUT, it is a gated, 55+ park with many park models and permanent residents. It is beautifully landscaped, but the only trees are palms. However, there are no derelict RVs, trash accumulations, etc. In fact, it has its own gated RV storage lot within the secure area.
The only negative for us at Rincon is that it is directly beneath the take-off flight path for every jet leaving Davis-Monthan AFB. I guess if you are retired Air Force, maybe you would be used to the noise. But I was in the Army and racked up too many hours in helicopters to love any jet engine noise!