Oh MS.
I'm in the same spiral.
Mom's not quite as demented as Mamaw yet, but well on her way. Great confusion at times.
I have a caregiver/sitter, uncertified but reliable (hell, saintly) 4 hours a day. Then she's alone, hopefully sleeping, for about 4 hours until I get home. She wears a LifeAlert type of emergency pendant, and walks with a walker. But she often decides she's fine with just her cane in the house, and I know one day that's why she'll fall.
I just can't arrange or pay for around the clock care. And if I went as far as you're willing to (e.g., sleeping beside her), I would go: a) mad, and b) straight downhill physically and wind up unable to do my job, and I can't risk that.
It's such a tightrope of cobbled-together solutions. It felt just the same to me when my D was little and I had to find child care.
Right now she's teetering on the edge of poor hygeine and I can't do it for her because of my back.
All to say, I truly feel for you and I am awed by your optimism that you can find solutions. I am glad you have a respite care backup plan.
love and steadiness,
Hops