As others have said, get power of attorney sorted. A mate didn’t when his mum was first diagnosed with dementia, and things have got very difficult.
My dads in a care home and mum still at home. She’s fit as a butchers dog luckily, but needs support emotionally as there is tremendous guilt on her part.
I live locally which helps, but just phoning regularly and talking has really helped her cope.
Even if you’re the other side of the world, regular contact really makes a difference.