To those that have space to keep a spare set of wheels/tires around, I
highly suggest a dedicated set of winter tires and a dedicated set of summer tires.
All-seasons are "no-seasons." A jack of all trades but master of none.
Snow tires really aren't just for snow. "Performance Winter/Snow" tires will give you maximum cold weather, dry pavement grip relative to a summer or all-season tire, while providing significantly better snow/ice performance.
The best thing about having a summer/winter setup is not having to compromise. You don't have to give up summer grip so you can have marginal winter grip. Instead, you get maximum summer grip and maximum winter grip. Have your cake and eat it too.
