You may have to ride more in the road after a snow fall, and if your route involves side streets it may actually be safer to ride on the better maintained major roads. In my experience side walks can be hazardous to walk on after a snow let alone ride on. Most places the roads are cleared and salted first then the sidewalks may get plowed. By that time the snow is packed and rutted and is generally treacherous until it melts.
Craig