Assuming that your horse has absolutely everything he needs (food, bedding, a warm stall, plenty of blankets, and a pasture mate he neither humps, maims nor gets abused by), what does your horse need to be the best version of himself?
I don’t think Robbye would need anything more than what’s necessary.
She is happy out by herself, so she doesn’t even need buddies. She enjoys interesting food but loves her grain, hay, and grass just as much. She doesn’t like working, though she does like careening around her paddock.
I think her answer would be: “I would love a pasture (no stall!!) with wide, flat, perfect footing for galloping and bucking. The grass would be really really really nice and tasty, and it would be easy to get to (no snow to dig through!!). The shelter would have at least one full open side so I could be half in the rain and half out of it. I would get some time by myself and some time with my buddies.
…And maybe Annye could come out every once in a while to feed me cookies.”