I had a friend who waited until her wife died before transitioning. Her name was Stephanie Bishop - and when she began transitioning, she was 79 years old.
She lost her friends and family on coming out, even her children and grand children were too conservative and short sighted to accept this - I know she cried many bitter tears over how nasty they were to her. But she was financially independent, moved to another city (where I met her) and got on with her life.
She was delighted by the tendency people had of underestimating her age by 20 years or more and endured many jibes about her "toy-boy" suitors who in many cases were twenty years younger than her. I doubt she was ever lonely again, as most people her age often are.