Last time I was in Portland, ME the fish & chips at Gritty's was so good we went back the next day for lunch before heading back to CT. Huge portion, super crispy and seasoned well (plus good fries too). If it's anything like it was when I had it, you won't regret it.
Gritty McDuff's Brew Pub | Portland, Freeport & Auburn, ME. Portland's a cool place to wander for the day, need to get back up this fall.
Ditto on spending time in Stowe, it's a great little town. There's a good swimming hole near the mountain I found last fall, was cold but worth a dip
Bingham Falls Parking & Trailhead · 6524-6892 Mountain Rd, Stowe, VT 05672
for the New Haven side, Stony Creek's a nice spot to have a beer. Though I'd agree Counterweight is a better beer for craft side of things, though I haven't been to their brewery yet. Lawson's is somewhere around there too I think and pretty popular.
Treehouse can be really busy, and has 2 locations now. Think 1 is just for takeout and one is for hanging now?
IMO New Haven is going to really extend your driving time and I'm not sure it's worth it. You can find plenty of other food/breweries without tacking on another 2-4hrs that direction. Dont think you had Burlington VT, but that's in the same general area as Stowe and may be a viable alternate
CT doesn't have toll roads. Mass uses pay by plate now so be prepared for some extra BS convenience fees from the rental car company. Don't think ME or VT have tolls anywhere.