If you have two bikes you can choose between each day, that would make things easier. Studded Tires if there is any (even 5%) chance you will cross any ice, re-frozen runoff, black ice, etc. Other Tires if it is cold and really dry.

Last winter, there were stretches of time where it was bitter cold here, but there hadn't been precipitation and wasn't going to be any... just white salt caked on the road... and the Other Tires were a nice, easier changeup from the harder pushing studded tires. The studs will save your bacon on ice, though.

The tire width is an interesting issue you raise. Both of my tire sets are 32mm width. I wouldn't want to go any narrower than that on my particular commute, because I ride at least a couple of miles of jointed concrete pavement with lots of unsealed joints, and those wider longitudinal joints can grab a narrow tire and throw a rider down. Nighttime makes them a little harder to see, and night riding is common for me in winter. With 32mm width, the joints are pretty much a non-issue on my commute. Do you ride concrete pavements with wide, open joints running parallel to your direction of travel that you have to be careful crossing?

If you only have one bike, I would recommend switching to the studded tires before the first Ice Event and then bearing down and riding those suckers until spring. It's slower and more work, but the safest bet. I have Nokian A10's, and they are dependable, safe tires.

If you have more than one bike, you have the luxury of equipping them with different tires and choosing each morning based on what's optimal for that commute there and back.

Good luck, post your experiences as you figure your approach out....