Portsmouth, NH, is a medium-sized New England town on the border of New Hampshire and Maine, off of I95. I think it is a good travel stop.
Downtown Portsmouth NH
If you are headed to/from Maine, Portsmouth, NH, and Portland, ME, are two of the larger towns with more choices for lodging. I'd say there are more activities available in Portland, but the downtown area of Portsmouth is more compact and easier to walk around. If you want to see more photos, I have a webpage of only Downtown Portsmouth.
http://kimbriggs.com/photo/new-hampshire/portsmouth-downtown
One block from the main street in Portsmouth, NH
The downtown area has a good selection of restaurants, bars and coffee shops. There is a Friendly Toast, which I just found has multiple locations around New England. There is also a fair amount of craft / gift stores.
https://thefriendlytoast.com/
Portsmouth, NH town park
Historic "Museum" Strawberry Banke
To get a break from the stores, there is a scenic walking area near the water, a town park with benches, and an area of period antique houses you can tour (small admission fee) called Strawberry Banke (link to more photos).
http://kimbriggs.com/photo/new-hampshire/portsmouth-strawberry-banke
I made up a joke about a euphemism we have in New England for tourists. When we say something is "historic" it can roughly be translated as "old and dirty". Ha-ha.
In all seriousness, I like Portsmouth and recommend a stop if you are in the area. I think it is a better overnight stop than Portland, ME, if you like a quieter, smaller town.