I hope he keeps well, but he didn't look like he had another 30 years left in him, did he?
Up the hill where I used to live we got vast amounts of snow most winters. I remember thinking to myself how am I going to manage living here when I'm in my 70s. Shifting snow was hard work, even with a tractor. The answer of course was I would not manage. In the end I moved before I had to.
I have to admit I don't have masses of sympathy for those who complain about high shipping costs, lack of broadband, high fuel bills etc because they choose to live in Granny's Heilan' Hame. Living out in the styx has a lot going for it, but it also has downsides that will NEVER be resolved. Only you can make the choice.
But getting back to the hermit - his circumstance is just an extreme example of this, but it's one that will be more difficult to get out of. The decent thing to do would be offer him a council house somewhere, Spean Bridge, The Fort - wherever - and then he can make the choice of which way to turn.