I definitely experienced some weird days when I lived in the Toronto area. I recall wearing t-shirts outside some days in February and like a week later it was -20C again. The western part of Canada gets something called the Chinook Wind which also creates a weird local weather effect.

I've never seen the frozen ocean before, other than maybe looking out an airplane window. Ontario does have a railroad going up to the ocean, ending at a small town called Moosonee, but I don't know anyone that's ever been up that far. I'm not even sure you can drive up there except during winter and running out of gas would be fatal.