I have thought about replacing the awning fabric with transparent greenhouse plastic, extending it down to the ground and enclosing the side of the trailer. If the trailer is parked south toward the sunlight during freezing winter temperatures, this greenhouse might increase the temperatures of the trailer above freezing point, protecting water pipes and water tanks.
I made this picture to illustrate my idea of a greenhouse awning
This could be a similar principal to parking a trailer inside of a hoop-house during winter.