some will say thin road tires dig into the snow better to give you better contact with pavement. some will say that knobby tires will get packed with slush and turn into ice tires. i ride road tires in the slush and snow, mtb knobbies in light snow or on ice/black ice (wider=more stability). from my experience and watching other people, you mostly need to do what makes you most comfortable and at ease, as your biggest enemy can be your own mind, and you can psych yourself out.
if you think this'll make you more comfortable, throw that tire on. and if it fits, i say front is better to prevent that wheel sliding out when you turn.