even without knowing anything about restricted access etc, when I saw your route, all I could think about is , wow that looks pretty darn remote.
I'm sure you can find other trail routes in the (sort of) area. I recall a couple of Vermont trail routes, names I cant think of right now, they've been discussed here in the past, but I cant recall the details.
One of them is a much tougher one, I'll try to remember or search for it---if however, a bikepacking route appeals to you, more for the adventure aspect of it, and not just going into the north Maine area specifically.
There has to be a bunch of fun offroad routes that folks have been documenting over the last 5 years or so.
What about the Divide route? Or part of it?
oh, and yes, the 2.5 Extraterrestrials are an interesting tire.I have a pair but really havent used them that much, just because I havent done trips that they would be appropriate for.
A friend used them when he did about half of the Divide Trail, and found them a good mix for the surfaces and still going ok on paved roads also. He did this in 2017 and I would have loved to have done it with him, but was just back from a long bike trip and couldnt be away again for a few months. He did it on a Troll and some panniers, and it worked well all in all.
I have a Troll also, and it and the Ogre are great, versatile bikes. I'm keen still on 26" and anyway, I have teh bike and it could go anywhere, just with a change of tires pretty much.
ps, you having good bike mechanic skills and hiking experience is a huge plus obviously for these types of trips. Some folks come on here with great ideas but with really little or no experience, and often seem to be biting off more than they can chew, or simply are being realistic about doing a given trip, or at least doing without a whole bunch of potential things that can go south due to not having real experience.