Edmonton does have short summer and long winter, and the winter is cold and lots of snows...
The Z, it can handle snow pretty good with a set of good snow tires, but yes, the ground clearance is going to be a problem with snow 5"+
I am not sure about the fitment for ski cos I drive a vert, hopefully someone can chip in.
If you have to take all those into consideration, how much space does the car have is a matter to you.
Don't worry about grocery shopping, the Z can handle it very very well.
You might have to think about the snow and fitment for ski, if you can fit the ski no problem, snow... unless you have snow storm all the time, otherwise driving Z on snow is not a big problem.
BTW, just asking, could you get a winter beater and leave the Z for summer?
cheers
CAD$0.02