I live in Wisconsin, and winters can be very frustrating here. I don't have access to an indoor arena, so I'm completely at the mercy of the weather.
Last winter was horrible, There was always a lot of ice under the snow, and since you couldn't tell where it was, riding was particularly dangerous. The only time it was safe was if we got several inches of the wet packy kind of snow.
So, over a four month period, I was only able to ride a handful of times
Some winters, the ice doesn't seem to be as much of a problem, but it's been bad the last few years.