Yes definitely. I suggest you build a run-in shed for them though. and when its cold or raining remember a waterproof blanket
Box
yes a horse does sleep.
Przewalski's Horse is the only remaining truly wild horse in the world. If someone owns one they live like any other horse, in a stall, paddock or pasture. But they are wild and live in Asia so they sleep outside in the wild.
Well, like any other horse, they sleep standing up!
If the horse is wild it sleeps with its herd. They normally DON'T sleep out in the open, but they sometimes have to. Domestic horse's either sleep in stables/stalls/barns or in a secure field.
the outside horse
Around 80% of dogs sleep outside, to give security to their owners.
a white horse sleeps by standing up
yes
Outside
Labs sleep in beds or outside i think
you have to sleep outside for 1 night, the full moon illuminating your body