We have stayed multiple winter weeks (not months) at Val Vista RV Park in Casa Grande. More permanent park models being brought in each year, but still have FHU sites for RVs. Paved roads, level gravel sites, pool, clubhouse, pickle ball, miniature golf, dog park, and lots of Midwestern neighbors!
Close enough to Phoenix to visit, but distant enough to avoid jammed Phoenix highways on a daily basis. Big Fry's (Kroger) grocery store within easy bike ride. Plenty of stores and restaurants right in Casa Grande for anything else you need. And the Tucson Gem, Mineral, and Fossil Show is a short day trip away!