There's loads of cool stuff in New Hampshire and the environs. If Peekskill is in serious contention, then there is good reason to check out New Hampshire, which is significantly better along most axes. I'd recommend that you physically send people to look around for a couple of weeks.
I will second the claim that being more than an hour from a city means most people will not casually go there.
I'd love to make a strong pitch for New Hampshire. There are a ton of people who are ideologically aligned with MIRI in the state. Taxes are low — there's no income tax or sales tax, and the state is actually lowering what business taxes exist. Cost of living is very modest. Boston is a relatively doable drive, providing access to a major international airport and a number of well known universities, and Dartmouth is in state. The state has a low intervention, libertarianish political ethos, and people are quite tolerant. The populace is also reasonably well educated by US standards, and the standard of living is similarly quite high by national standards.
I understand that finding an appropriate parcel of land would be important to the project, but right now the real estate market is very temporarily crazy because of people fleeing Boston during the pandemic; it is likely to cool down soon. I suspect that any one of a number of professionals and amateurs might be willing to help MIRI find a suitable location in any case.
In terms of natural beauty and quiet, the state has a lot to offer. We're currently living on a dirt road in a small town in the southern part of the state where I regularly take multi-mile walks to clear my head. The views both from our (very affordable) home and along the road are fantastic, and the natural surroundings here are the rival of any other place I've ever visited. I've seen a lot of the state over the years, and one of the reasons we picked NH was that it's very pretty.
In terms of safety, most of my neighbors, in both towns I have lived in, leave their doors unlocked. Crime is exceptionally rare in most of the state. (It is so different in this regard that takes quite a while for a person who is used to dangerous urban environments to get used to it.)
I'm happy to talk to people about the advantages of New Hampshire in other contexts.
I would also like to make a pitch against New York City and the surrounding areas. I was a life-long New Yorker until recently, and I love the place, but the problems of New York City (and the state as a whole) are not very different in the end from those of California. I think NYC is in for a decade or two of decline unless there's a radical change in the local political culture which is unlikely to occur.
I've taken the Edwards class; I can testify that the results were more or less as dramatic as what you see above. (One reason I took the class was that I thought that I was somehow mentally deficient in that I couldn't draw at all. Once I took the class and realized it was mostly about a very specific learnable skill that I had lacked, my desire to learn how to draw faded. BTW, similar skills are taught in Kimon Nicolaides' "The Natural Way to Draw".)
I think you will find that most of the more livable places to live in the United States require a car. The places that truly do not require a car are quite expensive to live in comfortably and often have other drawbacks as well.