In addition to battery life and cabin heating issues, there can be lots of small problems. I'm a bit worried about the fancy electric door handles, for example. I've been locked out of my car because the locks were frozen and sometimes even the doors themselves frozen solid.
I have no doubt that Tesla can overcome these issues but they will have to do extensive testing as well as make it known to the public that their car is a reliable vehicle even in wintertime.
People up here in the north tend to favor simple and solid cars and marketing Teslas and other electric vehicles is going to be difficult. The issue is half technical and half marketing.