Sottozero II are a great winter performance tire but not intended for anything more than light snow. If you are constantly experiencing large snow storms consider a more dedicated snow or studded snow tire.
My advice is when it snows lower your tire pressure to low 20s psi to increase tire patch (like you do in sand or mud), use Eco pro to reduce wheel spin, and use the manual shifter to take off in a higher gear to use more torque, especially when taking turns.
I have nokian wrg2 staggered tires on, which are more performance oriented than deep snow, and I had no problems driving in 4-5" of snow. I couldn't drive too fast and had to be conscious of front bumper height, but I rarely saw a slippage light. We get a lot of ice in New England too and the nokians are spectacular.