I’ll say Columbus, Ohio area fits the bill pretty well. Lots and lots of barns (largely thanks to Quarter Horse Congress at the Ohio State Fairgrounds) and equine services.
Climate is not as moderate as Portland, though. The summer will probably be a little bit hotter and the winter will be a bit colder.
Lots of shows, rated and schooling, mainly h/j but there’s definitely a fair amount of dressage. I’m unsure if the regular hunter pace circuit is still around. If not, I believe there is one up in Cleveland area and down in Cincy area, an easy two-hour drive each. Several lower level eventing shows as well, several parks with riding trails.
I have no idea about “quality meats,” I’m a vegetarian, but there were many local butcher shops I’d drive by, especially out in the country.
Great quality healthcare, excellent hospitals.
Great vets too, several large animal hospitals - Ohio State (not my fave), Woodland Run, Bella Vista (#1 in my book).
I’d recommend the Northeast and Eastern suburbs. Delaware down through Pataskala, Johnstown, Granville will have you closer to people involved in the English disciplines, and are generally considered the better school systems and “nicer” neighborhoods and such. West and South runs a bit more western (Marysville, West Jefferson, Orient) as far as events go, but still lots of horses and only a 45-minute drive to the other side of town.
The square footage house size might be a constraint in a LOT of locations, that’s a really big house! A quick Zillow search shows five listings with those specs. Another six or so if I drop it to a minimum of 2500 sq ft. Would you be willing to put on an addition, if all the horse facilities and stuff were already there?
What do you mean “no good?” I rode in Ohio in -10°F the occasional days it was that cold, thanks to having an indoor arena. It does a lot of good, even unheated. It blocks the wind and holds in some warmth. It was usually at least 15 degrees warmer than outside if the doors weren’t left open for long periods.