Cars older than 15 years don't exist on our roads. Sure, there's a survivor here and there but for the most part they all disappeared in a poof of rust. Junkyards are full of mid 90's and newer cars, most taken off the road because the frames/body's are Swiss cheese.
Since you're coming from AZ, I'm assuming you're not familiar with moisture. What doesn't rust molds or rots. I've had cylinder bores rust on engine blocks on stands in my shop, just from the humidity in the air and condensation. You leave any uncoated car part outside, it will be rusty/corroded within a week.
Don't even dream of taking the bronco out in winter. People have "winter beaters" for a reason, driving through the salt slush is a death sentence for every nut, bolt, bracket, frame and body panel, exhaust, ect on a car, no matter how well you wash it, undercoat it, or treat it.
You can drive it in the summer after a couple rainstorms have washed the salt off the roads, but I wouldn't take it wheeling either if it's in nice shape. The combination of mud, rocks, and most of all trees leads to inevitable body damage. Trails are narrow and overgrown.
New England can be great in the late summer and fall. Some parts of spring are nice. Winter may not be sub-zero, but the cold hurts more because of the moisture in the air and the lack of sun. Plus you get ice storms, where the rain freezes on the trees, the trees break, and the power lines come down.
Massachusetts drivers are a different breed for sure. Number one rule is to never make eye contact with another driver. Eye contact lets them know you know they exist, so they will cut you off. Your speed limits on highways are 75, and you drive 80. Our speed limits are 55 or 65, and we drive 80.
NH is better than Mass in a lot of ways. No income tax. No sales tax. No seatbelts or helmets required over 18. No insurance required. No title on vehicles older than 15 years. Nicer people, and less people in general.
Why does your wife want to move to Mass? People from here retire to AZ for a reason, the living's easy and the weather is nice.