Ours has several feet of the galley drain exposed, along with a couple feet of the main. I have a heat tape running along the bottom of the tube, with pipe insulation wrapped around it. That kept it from freezing when we lived in it last winter. Otherwise, no issues.
2014 Ram 3500 - DRW - 4x4 - 6.7L - 68RFE - B&W Companion
2015 Montana High Country 340BH