I think the winter mix fuel has more of an effect on the milesge than the cold temps. When the engine gets up to running temps the mileage should be about the same.
As for parking it outside, you didn't mention where you lived in the Midwest. In Minnesota during snowageddon 1 or 2 you might have a cold soaked battery if you park it for 36 hours in way below freezing temps. Those are times when you need it plugged in the keep the battery flowing.
As for parking it outside, you didn't mention where you lived in the Midwest. In Minnesota during snowageddon 1 or 2 you might have a cold soaked battery if you park it for 36 hours in way below freezing temps. Those are times when you need it plugged in the keep the battery flowing.