Oh Jeez, Jack! I sympathize and empathize. :-( My grandmother was one of the ones who killed someone first — one of her best friends. We didn’t know my dad was still driving till he mentioned casually that he went to see my uncle in Wisconsin an hour or two away! (His doctor stepped in and said No more!) My mother-in-law felt for several years that as long as she took small side streets, it was safe. Only my father-in-law gave up easily. Three of four had no dementia, just horrible reflexes. My husband and I decided years ago that we will retire someplace within walking distance from everything we need.
You obviously did the right thing, and I hope neither you nor Deb feel any guilt whatsoever. What we know to be right intellectually doesn’t always translate to our emotions.