Your post contained four paragraphs, which to me dealt with about the same number of questions. Because we are on somewhat similar trajectories, with me being a couple of years ahead of you, I offer you this advice.
First, focus on the Gulf side of Florida. You can go to Texas, Arizona, or California, but I believe that South of a line from Tampa across the State offers the best weather and snowbird experience.
Second, your best friend should become RV Park Reviews. Decide what level of accommodations that you prefer, e.g. resort, campground, cost, traffic, shopping, etc., and then do the research. To me, recreational opportunities, both in and out of the park, were important factors and my selection was influenced by these interests. In our locale, you would need reservations six or more months in advance for better or any lots in the months of January and February, but folks start leaving in Mid-March and April is very empty. We pay over $1,000. per month for a medium-grade site on an extended stay plan, but I have friends that camp in areas close by for $700.
Third, since we have grandchildren and because my wife dictates the holiday schedule, we leave the day after Christmas. If it were up to me, I would head South the end of October and come back North for a week in late December. I am lobbying my four kids and DW to hold an early Christmas on the Saturday of Thanksgiving week, and then stay in Florida until April 1. Still working on it.
Lastly, I am part of the minority as far as size of rig is concerned. Although we have a late model 40โ fifth wheel, we travel and stay in a 25โ travel trailer. The fiver is for our three month stay during summers in Traverse City, you know where that is, and the TT is our choice for the winter, due to a variety of factors. We also have two Golden Retrievers, but since we are active outside, the space really isnโt even an issue. We are not big TV watchers or lounge chair users, so you will have to decide what amenities you need for the quality of experience that you are seeking.
Good luck, the search is half the fun.