For me, the "average" time on my 5km morning commute doubled; but I did have to adjust my route adding about 6 blocks and walking the bike across 2 or 3 major intersections when bike lanes along with driver sanity became non existent. The time for the much longer evening commute on the MUP increased by 25% (when it was freshly plowed).

While this may seem drastic, I also changed bikes from a hybrid with 700c x 35 to a mountain bike (front derailleur disabled on middle chainring- 32T) with 26 x 2.25 (slightly under inflated), a more upright riding position and on the coldest days heavy enough clothing for snowmobiling/ATV riding.

On the coldest windiest days I felt I could have almost walked as fast on the morning ride, but it was worth it for the ride home (usually sunny and much warmer).

I "got by" without studded tires last winter, but they are on the list for this winter.