I started off full-timing when I was 69 and am now 74. And I travel alone and handle everything by myself, having put on 104,000 miles in the last five years. Plus, I have met some other women who are in their 80s. One told me she could not afford her house and her motorhome, so she was thinking of selling her house! Don't know if she ever did, but she had driven her 30' Class A from Maine to Utah.
So, no, you are not too old. Just consider that you are never going to be any younger.
And I am not even sure you need to be in perfect health. A lot of us have the usual aches and pains, and deal with illnesses, just like we would do if we were sitting in that recliner at home in front of the TV and vegetating. Better to get out and do things than die in your chair, which is what I told my kids.