If it hasn't been said elsewhere, Presque Isle also has a very, very, very small airport but it does have one and does commercial flights daily out to JFK (I think? Or DC), which should get you where you need to go if you need to travel from a connections perspective.

Aside: I left city life (Charlotte, DC, Seattle, elsewhere) for northern Maine (I'm an hour from presque isle) and love it. Presque Isle has all the commercial establishments you might want, but is probably missing the social scene - I've heard it's stayed subdued from pandemic. There is at least a weekly karaoke night??

It's a great English speaking area to stage your exploration of Canada. Quebec city is closer than Boston if you've got your passport! Plus all of New Brunswick is basically at your doorstep. I grew up in Fort Kent and Loved going to Canada almost every weekend. People are fun and friendly over the border and up around there!