When the snow piles too high on the roofs of their houses they get out a rake with a very long handle and actually rake the snow off their roofs. If they didn't the roofs have been known to cave in from all the weight of the snow.
Check for an electrical cord tucked in near the engine. Many rentals in that region have those and the engine oil will not get as cold if plugged in. You will probably need an extention cord to reach the electrical outlet. It's very common in January in that region to see many cars plugged in...