All-season tires are crap in the winter and crap in the summer. Will never buy anything like that. Anyway, winter tires are not only better where there's snow and ice on the road. The rubber compound is softer, so grip on cold roads will be better than any summer tire when temperature falls below ~10 celsius. Furthermore, winter tyres have better traction but also better sideways-grip which is essential in curves, breaking, everything. Last thing, don't forget that using winter tyres means that you don't add wear on the summer tyres during that time, i.e. you'll use them longer. So in essence, long-term, it's not more expensive to buy a set of winter tyres.