Sorry to disappoint.Hey CCC I was trying to research this a few years back but got sidetracked.....have you noted any desirable,affordable retirement centers or towns/cities with areas of intentional communities like this?
We're in Australia, and accessibility is a legal requirement in many places here, e.g. newly built retirement villages/centres. It would be relatively easy to find out with a phone call and asking about discrimination and disability access.
It's becoming a thing in urban renewal projects. In Australia, you tend to see it when a local council decides to 'upgrade' its main street. This usually involves blocking off a few blocks from traffic, making everything flat, putting in trees, benches and pavers, and creating disabled parking around the edges. The local library can often get some treatment around the same time. It's always one-off, and never systematic. Sometimes I suspect it's in response to legal action under anti-discrimination legislation.
Local councils need only about 5000-10000 people to be an entity - so the size of a small country town. (Numbers might have changed with council amalgamations in the past decade - but this gives non-Aussies an idea of the scale.)