Politics and culture play an outsized part. If I could easily move to Canada I would. Barring that, I'm more inclined to stick to blue states than red states. Montana is a bit of an outlier in my list. Cannabis legality is a factor (Wisconsin is the oddball here), but increasingly less so as I expect that problem to go away within a few years nationwide (and certainly in Wisconsin). Climate is a big factor. I grew up in NJ, and while I've lived in tropical places and tend to spend my summer traveling to a lot of hot places, I don't want to live in a hot, humid southern state. There are parts of NC and TN that are more more mountainous and less oppressive, but it's still pretty sticky there.
I still plan to spend much of the year traveling in an RV even after I settle somewhere. I'd be happy to spend the winter holed up in a cabin with a wood stove though.