Sorry, but I don't see the need for winter tyres. We have had cars for 100+ years and for most of that time they've had inflateable tyres, which were used at any time in the year - suddenly we have to have winter tyres? Perhaps tyre manufacturers have made their products last too long, which affects profits? Also we are (mostly) in the UK, we don't have sub zero temperatures very often, and normally when we do, we tend not to drive -or why not try the method I was taught - if the road conditions warrant it, slow down and leave a greater stopping distance? (wait for the screams!)
I believe winter tyres are designed to maximise grips at anything below 7 degrees - not sub zero. And wheels are bigger, tyres wider, and compounds designed to be softer at normal temperatures - all of which leads them to be less grippy in cold temperatures than they have been in the past.