I guess it depends on how far north you mean. I live in a State that uses lots of salt and it does a number on all vehicles in just a few years. On the other hand I wouldn't buy a southern truck that has been in a flood so it works both ways. As mentioned, there are lots of northern States that don't use a lot of salt so they may a good place to buy a used truck.
Our schools may delay opening by 2 hours during a blizzard or more than 6" of snow to allow road crews to get the roads cleared for the buses. We got 6" last night and I didn't even see any school delays. We do see lots of accidents but I think that's either because people forget how to drive in snow or are in too much of a darn hurry to slow down.