Welcome to OCDO Greg.
It doesn't matter what your home state might be. When you are in another state/jurisdiction, you must obey the laws there, regardless of where you live. That being said, both NH and Maine allow OC w/o a permit. Careful in NH though as a permit is required to carry loaded in a vehicle.
A "Cliff Notes" peek available here:
Research and know the laws carefully yourself before entering states new to you.......and carry a good digital recorder.