This will vary tremendously based on your income level and what you're looking for in a place in FL, so what's worked for some may not work for you.

Several folks I know who have done it opted to rent their primary home out for 6 months (Nov-Apr), and either had a fixed place down south or every year hunted down a different place to rent for 6 month.

However, and oddly enough this seems to be the more affordable route... Someone else I know bought an old liveaboard-sized boat for cheap (at auction it was cheaper than a car) did some minor repairs and now lives on it at a Florida marina when there and leaves it locked up when not. Many of these "liveaboard"-focused marinas are between $10-18/month/per-boat-foot which often includes electricity, cable, wifi, amenities, waste pumpouts, etc. Downside is insurance costs can be a killer depending on the boat and location. But hey, waterfront for cheap!