Good tools mean little if you don't know how to use them or you go panic. Snow storms are bad, frozen lakes other. When there's - 20 degree's C and wind blows, you loose rapidly your body heat. Wind is the real killer.

Its been 10 years since army, I've forgotten most things I learned in winter and wilderness survival than I remember. You should never go "practise" alone or without professional. The survival course don't cost much, are fun and might save your life. I should go one too to refresh my skills.