Can I Drive on Cooper Tires During Snowy Weather?

I'm planning a trip to the mountains this winter and was wondering if I can safely drive on my Cooper CS7s during snowy weather. The tires have a M+S rating but I've heard mixed reviews about their performance in deep snow. Some people swear by them while others claim they're not ideal for such conditions. Has anyone had experience with these tires in heavy snow? Do they provide enough traction or should I consider switching to a dedicated winter set-up before heading out?