I ride 6 miles round trip everyday through downtown for my commute. It’s very doable within downtown NH, once you start heading towards WH it gets significantly less bike friendly. I take the Farmington for a good chunk and that’s all good. Roads downtown aren’t bad either but like others have noted you will be on the defense, just always be aware of your surroundings and take up the lane if you can. If you don’t feel comfortable with the traffic, just take the sidewalk.

Once you start hitting WH you’ll notice drivers being even less cognizant of their surroundings and speeding and what not. As others said, I would avoid the blvd and any busy road. You really can’t trust drivers in that area. ALWAYS bring lights and wear Hi vis gear, especially now that it’s getting dark around 4 pm.

I think the Bike + bus/train might be your best combo as others have noted. May as well do the bus over the train since it’s free.

Good luck and safe riding!