Ice tires for winter commuting on non-icy roads? Can a tire like the Schwalbe Marathon Winter be used for winter-long commuting (40 km/day) on roads which are mostly or usually not icy?

I might want the studs occasionally (and lower the air pressure to get them), but not on most days.

This is Toronto where it's subzero at night, with snow etc., for about 4 months (it's snowing today for the first time), but they plough and salt the roads.

I wouldn't want to have to swap the tires daily or weekly depending on the weather: only once a season.
I think the tires would be durable enough (my winter commute in nearby Kitchener, ON is about 20 km/day and my Marathon winters hold up pretty well) but they're definitely going to feel more sluggish than a road tire.

If you're normally running them with enough air pressure to keep the studs clear of the pavement, I think that kind of defeats the purpose of them (and that much pressure makes the ride a little harsh for my liking as well). Carbide studs will last as long as the carcass of the tire holds together, and there's always a chance of running into an icy patch somewhere, even if 99.5% of your route is bare and dry.