I’m in the upper midwest. I don’t have a barn (yet). I have two dry lots, two sheds (one is matted and 12x18 with a gate) and a pasture. My water and electricity are right there and the area is well lit. I breed in late May, early July for a mid-May foal.
I ship my mare to the vet clinic to foal out. I leave them there for 5 days or so, until the vet is giving me grief about needing the stall. Then I bring them home. Also, my horses live with two donkeys, who hate dogs and coyotes and my paddock is all hot (my dogs will not cross it, so I imagine others won’t too).
I had to do stall rest for a mare and foal two years ago and you may too, so I highly recommend a couple shelters and the ability to make one into a stall. It is not uncommon for a foal to be born windswept or with some condition requiring limited turnout.
I wean by boarding the mare off-property. For my last foal, I had a very nice elderly thoroughbred mare that I was fostering for a rescue (who had also had foals) and she was the perfect babysitter. She also taught the filly the manners her mother hadn’t bothered instilling.