Hi Diplo! Always good to see you posting here. I received a text message that you were asking a question. When I read your message (twice) I see that the message is more about what campgrounds are in fact, open. If you need to get some tips on Stealth Camping, off the grid, in temps below 20*F I can certainly make some suggestions. (Temps above 25*F you should be perfectly fine)
There is an article on, Stealth Camping, coming out in Truck Camping Magazine in a couple of weeks. It will have many good tips, I guess young people call them "Hacks" now, but it won't help you here, now.
Looks like you are getting some good suggestions on campgrounds from the great group in this forum. I am the last person to give advice or suggestions in campgrounds, as I just used up my quota for campgrounds for 2015.
Enjoy the Northeast and stay warm!
b