What support system does he have there? --Partner or children? If he's on his own, might he consider moving closer to you? --I was prime care-giver to my father from 1000 miles away. It badly affected both my career and my well-being in other ways. Dementia tends to do that to the prime care-giver, no matter the distance, but there are certain unique difficulties to trying to help someone when they're so far away.
The trouble is the illness has a way of leaping ahead of clever solutions. We gave my dad an iPad for his calendar appointments: his friends would tell me when they were, I'd fill them in on a cloud and set alarms. he loved the iPad for all of a week. Then he said it was broken. He didn't realise he had to charge it. Before we knew he had forgotten how to turn on a computer.
So true. I wonder how long Mum will be able to continue to use the PC. Right now she finds it useful but... well, we'll see. While it's there, though, it's a useful way to help someone abroad or far away.