Look at the weirdly regular outline on the ground! I infer there must have been a larger structure where the garage is currently - a barn, maybe...? - somewhen in my property's past. Do you think that's a foundation under there?

I think my yard is a tiny bit warmer than most of the other houses' open space because of my trees. It took an unusual freeze where I used to live for me to be forcibly reminded that trees too generate heat because they are living things.

there is a pad of concrete most likely a previous garage, double the width of that one if it's single width.

it's the exact shape.

Isn't it though! The house was built innnn... 1896? Lots of mods, like the laundry room and ground floor bathroom seem pretty much like addons at some point or modified after the fact. There's a staircase that goes up to the second floor except there's a floor in the way now (make a great storage closet), so the attic was transformed, too.

And this whole area was probably farmland at first, too. There's a tiny town-center-type area built around a grain silo that's a mile or so away, for example.

Other option: the shade of the building kept the ground colder before it started snowing.

The garage isn't all that tall, and the snow was at night or dawn, so shade seems unlikely.

What a discovery, though! Hidden architecture via snowfall.