You'll like it.
I have ridden via US-2 from Plattsburgh NY to Bangor, and I enjoyed it all. From Bangor, I went east via ME-6, via MacAdam NB to the capital. On the way back, I crossed from St. Stephen to Calais ME, then ME-9 to US-2 again.
The above ride was in 2007, but last year I covered much of US-2 in a van. Not much has changed. The pavement is good enough, and I do not recall seeing any dangerous conditions.
But there are other routes, and any advice you can get from Black Lab will help you. He has ridden all over Maine and the Maritime Provinces, including much of Québec. Read his posts before bothering him, please, because he is busy building an airplane, and he may not wish to show you where he has already answered your questions.
I agree with your plan to stay in Gorham NH. I did that in 1951, when it wasn't
my choice, and again in 2007 when it was. Last year I just drove through.
If you make contact with the New England Stromtroopers, you may be invited
to dine with them, and they may ride part way with you. Happened to me.