I'm not sure anywhere in NH will qualify as "big night life". I live in Sunapee, moved here in 2020 from Worcester, MA. Previously lived in Portland, OR, OKC and NYC. Wouldn't choose anywhere else.

I wouldn't characterize Sunapee as a "farm town". It's a lake town in the summer, a mountain town in the winter. Night life is a couple pubs, some community events in the summer. The larger area, The Upper Valley is pretty quiet as well by city standards. Lots to do if you like being outdoors. Some great breweries, some good (not great) coffee spots and restaurants.

I will say there is a bus to Boston from here that runs about 10x daily. I use it to get to Bruins games, but you could certainly utilize it for nights out.

All that said, the lifestyle here is not city life. You go to the transfer station instead of having trash pickup. You drive 20 minutes to the grocery store and if you're lucky there is maybe one restaurant that delivers food to your house. It's slower here, so bear that in mind if you're considering the move.