2010 and 2011 Winnebago Vista 30W Owners

Question for RonDeb specifically, and any other PNWers with a Vista, and generally for anyone where the winter climate isn't quite so severe.........Is there a method to keep the motorhome safe from freezing up, without having to winterize that has worked for you? I would like to use our coach all year, and we're planning a trip down along the Oregon coast the end of December through the first week of January. I would like to figure out a way, short of having the furnace running all the time, to keep the fresh water tank, pump, and lines from freezing without doing a complete winterization. I know that I can winterize all the lines, and then take jugs of water inside the coach to use for flushing, cooking, etc., but I also want to use my shower, hot water heater, and everything else if possible. Does anyone have an idea on how to keep stuff warm enough without using the furnace and without winterizing? I have the heat pump on mine, but that doesn't work once it gets down to just above freezing levels, so that's not an option. I don't think space heaters would provide enough heat to the compartments where the pump, tanks, and pipes are located, and they cause condensation to build up inside from the windows, especially the cab, I'm thinking. Is there an easy way to keep everything available for use without going through the whole winterization thing, other than heading south for the winter, which isn't an option! :>)