Retirement communities, like The Villages, aren't for everyone, but my folks moved there in 1999 and absolutely loved living there. My Dad passed away two years ago, but my Mom I don't think will ever move.
Another option to the garage, might be the lanai (sun room). These rooms are often finished and heated/cooled. Villagers loved their lanais, and my Dad ALWAYS drank his morning coffee and did the daily crossword on theirs.
In the Villages, I would opt for a room at ground level instead of a room over the garage. Much easier to sell the house if y'all ever decide to do this.
I have never been to one of their events, but The Villages does have a model train club, with subgroups for each of the 7 scales, including O.
Jim