In most of the (winter) climates I've lived in, it's foolish not to switch to winter tires. Sure you can sometimes get by without them, but they can also save your life. You can "get by" without a lot of things, until you have them. Then you won't want to go back. No season tires, as I call them, are by nature a compromise. Some better than others, but none will be as good as a dedicated winter tire. Even with my AWD Audis, they all have a set of snows and/or studs. Critical for going, stopping, and safe handling.
I've had a set of 215-50-17 Nokian Hakkapelita R2s sitting in my basement for a month or so, waiting for Boltar to roll in on a train. They are fantastic winter tires, studless, and don't have their winter tread stop at half tread depth like Blizzaks do. Got them pretty price competitive with the lesser tires online. I've used most of the brands of winter tires, and these are by far the best studless winter tires I've used (they're also on the wife's car). As a bonus for the Bolt, they are low rolling resistance. Not sure what that means exactly for a winter tire that's designed to have as much traction as possible---kind of like I haven't yet seen a Z rated LRR tire--but they indicate that it is more LRR than their other compounds, for example.