Maybe keep this option back of mind while he goes through the winter and further stabilizes his feet.
I just went through this with a horse who had been living comfortably, mostly out, but with very little pasture. And with necessarily shod feet. And a thoroughly attached best friend – that was the hardest part.
It took some time but I finally saw enough signs that it was time to make the move to the larger pasture, with horse friends, living in a natural small herd.
My horse has done well. I think was ready to swap his old bestie for grass. He’s got new friends. It was hard for him for the first few weeks, as he hadn’t been off the old property much since covid. But he weathered it, as they all do. He settled in quickly and no longer looks for his old friend.
Maybe this will help – when you are with your horse, occasionally have a mental conversation with him about the options. You may feel as if you are getting a clearer answer. You may also find yourself thinking more about the fallback options if you do make a move an he doesn’t feel happy – can you keep the door open to return where he came from? Can you spend more time with him at a new place? And so on.
There isn’t a perfect solution. Don’t feel stuck because you don’t feel you can assure every positive outcome, with no negatives. Rather, be prepared for some things that are less than ideal. Balance the tradeoffs, the pros & cons, as they say.
Sometimes the answers find us, if we keep doors open to answers we hadn’t yet been thinking of. 
