The woman is in her 70s - it's going to be physically very hard for her.
I had carers to help with Mum but had the night-time care to do for her and sometimes had to help DH during the night.
I had to help a carer with Mum in the morning and get DH up and breakfasted before I went to work.
Mum died when I was 55. By the time I was 58, I finished up taking early retirement. Even not working, I was exhausted because of broken sleep.
DH was compos mentis, but i had to help him with his showers. On bad days, I helped him on and off the toilet. I had to deal with his meds, sort out the creaming of his legs and feet, etc.
As time went on, he needed more help with being lifted off seats, on and off the toilet, etc. Latterly I was helping him twice a night with a urine bottle and that was very difficult - I'll not go into it all.
DH has been gone 5 yrs now and I still don't feel fully recovered. My sleep patterns are all to pot; as I said above, I needed a shoulder decompression because of the lifting. Latterly, we got a bed raiser supplied by the council, but DH still needed help getting out.
From what the OP has said, her father is in a much worse condition than my husband. It sounds as though he'll need a hoist and that probably means moving furniture around and so on.
I note that the OP has said that she and other family members will likely have too much on their plate to step in. All I'll say is that it would have made a world of difference to me if my DH's adult children had very occasionally sat with my husband just to allow me to go out without worrying. I don't begrudge my husband anything, but the stress alone was debilitating. I miss him every day, but I could have done with more help.
We were given interim care when he first had his stroke, but the Home Care team manager took one look at me and cut it all. We were given a little bit of help at the end, after his last hospital stay but then it was all on me again.
More help from the kids - even just in organising things - might have made a difference. NB One was working from home, but the other had had a very good job which meant that she'd been able to retire well before 50.
I think that the OP is being rather shortsighted if she thinks that a woman who is in her 70s is going to cope with the physical side of looking after a full-grown man. Being fit in your 70s is nothing like being fit in your 40s.