Is the pump installed at the well or at the trailer? How far is it to the water from the top of the well? What is the elevation from the well to the trailer?
We need this information before we can make any recommendations!
Other than that it should pump water if it did before freezing, if the pump isn't busted (from the freezing) and the lines from the well to inside the trailer aren't frozen or leaking from the freezing and the pressure switch didn't freeze.