Dude. Nasty weather on the way.

But, yes, state parks, you will have them all to yourself.

One tip, use two sleeping pads, one closed-cell foam on the bottom, then your inflatable.

Just step onto the AT out in Lee or something and post up your tent wherever you want along the trail

if a guy with a shotgun or a machette enters your tent.. do you have guns to defend yourself??

There's a backwoods camping area near Alander Mountain; check with the Mt Washington State Forest headquarters out there to find out if the sites are open. This is in MA, not NH, it's in the western corner of the state near NY and CT.

There are camping areas next to shelters all along the AT.

Check out the Blue Hills Reservation.

I'm an old guy who spent most weekends up in the White Mountains when I was in college, late 1970s. Long time ago.
Go when there is snow cover and full moon, you can see like it's daytime. As long as it stays below freezing you won't have moisture issues other than sweat. After getting to get to your spot, CHANGE INTO DRY CLOTHES. You'll never be warm if you're wet underneath.
Boil-in-bag meals makes having hot foods easy. Then you can use the water for wash up.
It's beautiful out in the wilderness in the winter.

State Parks are your new friends...

https://www.mass.gov/camping-at-massachusetts-state-parks

Don't wear cotton, I would try and find some bomb proof boots with removable liners to dry out

Thank you wise soul ❤️ it’s so cool to be able to talk to older people and read what they say

small, but important detail: make sure the foam pad is full length. Otherwise you’ll lose a ton of heat to the ground and it will suck. And you won’t get any sleep.