John, this brings back what my gf went through with her mum last year. It was even more stressful as her mum lived on Vancouver Island and S is in Bellingham WA, so she had to cross the border and take a ferry, in all, about 5 hrs. travelling. So even regular visits over the years were time-consuming.
She had lived independently in her small home, with "the two things that made life worth living"- her garden and her cat (one of many over the years) but eventually she couldn't cope as a melanoma she hadn't attended to in time began to spread last winter. We had hoped to find a place for her over here on the mainland where we could both visit easily but it was not to be.
Long story short, S went to visit over on Easter break last spring, eventually having to extend her stay and do some lectures online from her mum's place before Ma had to go into Palliatave Care, which was superb. S was run absolutely ragged by the strain of that visit and was sitting on the curb in tears with the cat in its carrier, waiting for the local cat shelter to come and take him back. (He had come from there and knew Ma and the cat quite well!) Then she drove to the ferry. She had a few days at home, then had to go back. I went over to be with them - also about 5 hrs and a ferry, although no border to contend with. Ma died at 94, fortunately fully compos mentos right to the end.
S still doesn't know how she coped wth the strain, which subsequently involved going back to organize clearing out the house, but she did. She simply had to as there were no siblings. I went over a few times, too.
But you've done the right thing, as painful as it is.