We tried Texas, Arizona, and Florida. We actually didn't stick with Texas and Arizona more than a short season. For us Texas just did not have the best winter weather. Arizona was okay but for some reason the DW likes water.
South of Sarasota (Florida) is where you will get the best all-around winter temperatures.
We are in the Fort Myers/Fort Myers Beach area and have been the past two years. I do a 4+ mile walk every morning that takes me though 4 RV resorts, all of which are within 2 miles of the Beach and a little over 3 miles from Sanibel Island.
Gulf Waters RV Resort: sites are all RV's, size lots are about 50'x120' surrounded by landscaping. Extended winter stays run about $1,500 a month, but that includes water/sewer, electric, internet, cable, taxes, everything. Pets welcome.
Indian Creek: sites are mixed park models and RV's, size lots vary and are small. Small roads but well maintained park. Rates are cheaper but everything is an add-on. Overall the monthly winter stay rate would probably be close to $1,100. Pets welcome.
Siesta Bay RV Resort: sites are mixed park models and RV's, size lots vary and are small. Roads are bigger than Indian Creek. Rates are about the same or maybe slightly higher than Indian Creek because everything is an add-on. I am guessing, depending on your electric use you would pay about $1,200 a month in the winter there. No pets allowed.
Palmetto Palms: Owner/Owned park with 90% park models. Some owners have vacant lots they have set up for RV's. RV size limit is about 35'. Rent charged depends on individual owner but runs somewhere $400 and $700 but you have to add electric. Sites are not that big but this is a pretty nice park.
Pets only allowed on perimeter lots.
My point here is, if you want really good temperatures and want to be within a bicycle ride of a beach, then you may consider one of these parks for a "first year experiment" of this area. We stayed at Siesta Bay last year and liked it, but then while down here we checked out Gulf Waters and made reservations here for this winter.