A lot of these people are moving into their vacation houses so they already know the deal. Jobs and their kids schools kept them in the city or nearby burbs. Also many of them are on the wealthy end of the scale and at the moment quite content with online ordering their fancy pants. Yes there is the weather, lack of yoga classes and a few other things but remember the alternative is going back to the land of the deadly sniffle plague. Considering their job and their kids schooling are no longer location driven and 'home' is full of a scary disease and I think the fear will overcome the few drawbacks. Word I hear from VT is the newlanders are already meddling in town politics.
Maybe in the case of the vacation home folks, short term you could be right. But long term, no way. Moving permanently from the MA/NY/NJ metro areas to rural NH is no simple adjustment. It sure as shit wasn't for me, spending 8 years in Boston and then moving to Nottingham. I've lived in a few towns in NH and in none of them did I get the sense that uppity outsiders had any chance in changing the status quo.