Good luck with your game. I played a solo peasant knight game long ago when klaravoya prepared some challenges for us. Playing that one is a bit masochist to be honest because of the lack of spells. It's perfectly doable without having a second character though, as you said, npcs can help with fly and the like.

I remember that crossing the sea to hermit's isle was really a pain. I learnt afterwards that you can drink a potion to have spell points to use a fly scroll.