We understand your concern, especially at this time of the year, when temperatures can vary drastically from one day to another and even in a matter of hours!
Parking under a power transmission line is not particularly dangerous in any way. Our equipment is designed to withstand the forces of Mother Nature, including freezing rain. However, in exceptional circumstances, it is always a good idea to be cautious around any structure or equipment on which ice could accumulate (roofs, trees, street lamps, wires, etc.).