Certainly I could insulate any of the hot water line that I could access. However, I'm not convinced that would solve the problem and may create more trouble.
In my experience with plumbiing houses, pipe wrap is good and bad. The bad is that once the pipe is filled with hot water, it takes a long time for the water to heat the cold mass of the pipe wrap around alll the line. Consequently, you run more water at the tap to get hot water, because the cooler mass of the pipe wrap takes the heat away from the initial hot water passing thru the pipe. Running extra hot water out of my limited fresh water supply and 6 gal HW tank is not what I want to be doing.
Besides, the temps around the trailer were in the 80's and 90's this weekend, so I would think that the lines would not loose much heat once raised to equilibrium with the passing water.