I've kind of avoided this thread/topic, but OK, I think I will contribute.
This was very close, if not exactly, my situation.
I don't think children "owe" their parents anything, if it's done out of mutual love and understanding - and it's not unreasonable, and all support systems, medical advice, etc., are being followed - sure, help as much as you can within that framework.
To frame this: my Mother was living alone several years ago (Dad died in Oct 2015, can't even tell you the exact date), we offered to help her move closer (~1h and 10-20m away, bad drive, terrible traffic and accident area ...), into a nice condo complex 10 minutes away, or a house in our area, or even, doing something with this house, add-on, whatever, would not. We volunteered several times to take her to Dr appointments, she always cancelled, twice on my wife after she was almost there. I made dozens of suggestions about improving her life experience, getting her a wheelchair (vs. her walker), buying a nice van with a side lift. No. In my professional capacity, I work closely with physicians, and have a good friend who heads up internal medicine at a local health care group who made dozens of recommendations, would not follow any of that.
She did listen to one of her ignorant sisters, because of instead of offering good sound medical advice, she said all doctors are terrible, and I should do more.
Then, well, I'll cut this short as it's a whole narrative in itself - full of complete, life (mine) wrecking chaos, psychological impact on my whole family, loss of thousands of dollars of work - she wound up at home, bed ridden. Now, she didn't have to be in that state, she refused med changes, and refused PT/OT, and refused to use a wheelchair, or a transfer board.
Now she needs near full time assistance, and there's no option here (the US) for compensating a non-medical professional, either you get some at home medical care (which has nothing to do with things like meal prep), or you move to a care facility. At home care, is out of pocket, because it's basically "sitters", meal/maid service, and personal hygiene.
At this point, wy wife and I were supposed to do this, 24/7, without regard to our daughter (her only grandchild), either selling our house and moving or making that 1+ H drive 7 days a week, or whenever, as needed, because she continued to not listening to medical professionals and only to the couple of sisters (and a niece) who basically condemned me for not losing my clients, my health, and helping to raise my daughter - this is ol' school southern thing too, everything should be about Mother, kids should live down the street, Mother should take precedence over your own life/job/health, wife, child, etc.
Thank god I had one cousin, who helped a ton (especially when I was travelling a bit more), I mean, it was also because of "southern guilt" because she lived with my folks for a whole - oh, and that was always brought up, how much my cousin "owed".
So she tapped into her savings, went through $220K+ for at home care over about 3 years (that still involved me 7 days a week, because she raged at all the sitters, at least 20 of them quite over the 3 or so years - she was EXTREMELY DIFFICULT). I hope it made her happy, I didn't need or want any of that money. She died in a nice hospice facility, after a downturn, and basically I told the doc, I think this needs to end, he couldn't believe her condition, he vehemently agreed, got her pain under control, deep sedation.
When she passed away, it was the most relief my family had in 5 years.
BTW, when I say family, I mean my wife and my daughter, and my "extended family" is my DIL, BIL and cousins/aunts on my wife's side. Her family can mostly just fuck right off, I never speak to them expect for the one cousin, who occasionally pings me (to ask about me and my family) and one aunt who's still sends me random "thinking about her" messages (for the record, I've had almost no contact with my Dad's family, ever, and none in the last several years, which is fine by me ...)
I'll be honest, we talk about her now and then, over some -ism of hers, same with my Dad (his story is different, but the same, and somewhat a sad tale because of my Mother's inability to follow medical advice ...), but I don't stop on the day either of them died, I don't use it as some demarcation point in my life, I think of some of the positives (especially in the case of my Dad), and look forward to the future with my amazing wife and daughter.
@Eric Yeah, once you get to the "This is a much as I can do, and I don't have any regrets about not doing more than I did" in your head, it's a good place.