I would like to say that although some all season tires say they are all season, they are just not designed to handle all of winter's road conditions. I say this because we have replaced several almost brand new sets of tires because customers could not get around town and up their driveway with good traction, confidence and peace of mind.
A tire that is an "all-season plus" traditionally has the mountain and snow flake symbol which designates that the tire is designed to handle winter conditions. I have attached a picture of the symbol.
If your slipping, sliding and want your tires checked, then stop by the garage. We would be happy to check your tires for you.