Our next door neighbor's son that lives in the Hartford, CT old female schnauzer did do that here in the last week or 2. Fortunately they realized it right away and I think the dog was by the front door when they paniced and went looking.
Now it seems to me, my first winter or two on newf.net before Snuffles was even mine, someone here from Canada had that happen, but fortunately found the dog right away. But they took pictures from a 2nd story window of the foot prints in the snow, and you could see where the newf went over. Seems to me the snow was within inches of the top of the fence. I had tried to see if that was still on newf.net awhile back ago, but could not find the thread.