Well, that would be considered extreme conditions so would have to replace sooner than normal. They still make the winter blades that have the covering that goes over the frame of the blade to help keep the ice and snow build up from getting in to the frame, holding the rubber insert, and that would cause the insert to pull away from the glass at different areas along the length of the blade. If you leave the windshield with ice and snow on it and use the defroster to help clear and use the blades a little at a time to push it then the wiper wears out quicker. A properly cleared windshield before you start driving will allow the blade to last longer. Plus, if you get salt splashed up there and the blade works through that then the blade goes south real quick.