My answer - the earlier the better.
There are few reasons why you move to such a place CCRC (Continuing Care Retirement Community).
1. You have retired from work but not from life, so you need a community where you can be alive with many activities and enjoy your hobbies. Keep you "young."
2. Avoid loneliness. Loss of a spouse on a man is harder than on a woman. Having a great support structure of people in such a community keeps you away from going bonkers with loneliness and getting depression.
3. Time comes when the "machine" starts breaking down and you don't want to burden your spouse or kids. This becomes a nightmare with a neurological disease like Parkinson's and Dementia. A person can live from 7-12 years making it extremely hard on the caregiver (Saw it personally with my brother. His wife took care of him for 12+ years and then she died also in 2 years with colon cancer. Miserable years of their lives. The cost of nursing homes is prohibitive, and most are subpar. Long-term insurance is expensive and not adequate.
After 5 years of three cancer surgery and an awful near-death Chemo, we moved to a 5-star resort place CCRC for the above three reasons.
I have created an exhaustive document on why one should think of going to such a place, and how to choose one. It is an almost 40 pages long document with many resource links and books.
You can get it at
https://docs.google.com/document/d/1TkRo92IWiiSWGh6QrfqN-YDpq0ge34HLmz0-zvkYnU4/edit. Feel free to contact me if you need more guidance..