With this recent COLD snap, you will find that other trailers will have this same problem. If i was down there, and had been watching the weather forecast, i would have taken precautions regarding frozen water lines. Education can be expensive some times. Our FD responded to 53 broken sprinkler lines yesterday. When they put these sprinkler pipes in, they take precautions, but i guess not enough, so when it gets to -20 with a wind chill of -45, these things happen.
Drying out the camper is a #1 priority, then wait an see what needs repair or replacement, as for schematics of the water lines, your best bet is the trailer MFG,