I found this picture of their typical mode of travel - this one was labeled "Big snow of 1915." They were off on a round of visits to neighbors and relatives.
These last two are from "The Blizzard of 1949." By this time, my grandparents had moved into town and my grandfather had a rural mail route. He had to use his own car and according to the caption, also dug out the mailbox you see pictured below. That certainly doesn't happen any more! Compare these to the pictures of my big snow and mailbox here.