In the past when we were expecting a few nights of cold but then a long stretch of warmer temps afterward I would use the heat rather then winterize.
If the lows at night were predicted to be around 30-32, I would turn the heat on the lowest setting. I would also leave the cabinet doors open below the sinks to let the air circulate near the plumbing. I think the camper will naturally retain some of the heat that built up during the day, and, combined with the heat it should stay well above freezing over night. I would also close windows and roof vents to hold in the the heat.
If the lows were predicted to be in the high 20's, then I would be cautious and add antifreeze or blow the lines. I have done this many springs after de-winterizing and autumns before winterizing.