We are in a very similar climate to yours and I have to say that if you plan to use a tractor here in the north in the winter, especially for snow removal (especially w/a blower), a heated cab is damn near a necessity. I cleared our mile of driveway on an open tractor through the seventies and early eighties and it was brutal. In '83 we bought a cab tractor and it has made a nearly impossible task merely a routine chore. Our's is an 80hp rig that is 10' to the top of the cab and requires a bit more branch pruning along the woods roads but that is not an issue for me when compared to sitting on an open tractor in lake effect snow at twenty below zero for hours at a time. For the most part, I try not to do my wood gathering in winter and mostly use one of our smaller, open platform tractors in the woods, but on occasion will use the big tractor to skid logs or haul the big dump wagon without issue.
You do make a solid point. We don't get quite as much snow, but the wind coming off the coast is pretty brutal. I will definitely consider the field cab.