Anyhoo, back to the OP, I would get a set of studded tires. It sucks to ride on them when it's dry and clear, but because you're commuting road conditions change during the course of the day and night. It's worth it's weight in gold if you can avoid calling on difficult-to-see-thin-layer-of-frozen-water-that-appears-black-to-the-eye-and-misnomerically-called-black-ice ice.
Last December I hit hard-to-see ice patch and went down before I even knew it. It happened so fast. One minute you're riding along on dry pavement, and then you find yourself in the middle of the stuff. Fortunately I was approaching a stop sign and so going relatively slowly. Actually, come to think of it, it might have hurt less if I'd been going faster.