I hope I am not crossing red lines, but I could not envisage giving up my house (which is easy enough to manage) for something a lot smaller, or a flat whether in a retirement complex or not, at my age - 75, in full possession of my faculties, driving and although now widowed, with a full social life -Arts Society, theatre and films, book group, friends.
As St Augustine didn’t say “Give me downsizing- but not yet”
My half brother did this after he lost his wife but now finds he still only infrequently sees his busy GP daughter, and the GC who are nearing their teens, are leading with their own lives. It has been only a qualified success and he sometimes sounds a little regretful for what he gave up.
I can see the relevance of distance for GM but to move to be close to AC without one’s own “way in” to a community seems to me to be risky. That way in, could be a hobby, church, choir, or a historic link with the area, but (for me) not just my AC. I don’t want to be “X’s mum” - I am me.
Moving with one’s DH is different, it is always easier to establish oneself as a couple. So if I were to downsize, I would choose to be an accessible distance but not too close as I would feel their absence all the more when they were busy leading their own lives. Think carefully about what an area has to offer you as well as what you have to offer it. And weigh up all the pro’s and cons!