Winterizing our trailer on our return trip to Canada

You could purchase a small compressor and blow the lines out before you get to the area it might freeze. You can purchase an adapter for a compressor at Camping World or Amazon. Bypass and drain the hot water tank, drain black and grey tanks, hook compressor to city water, blow out all water lines with 30 psi pressure. Don't forget the toilet and outside shower. Dump RV antifreeze down all drains. You can find videos on YouTube showing how to do this or the antifreeze method as others suggested.
Good luck.