I wouldn't take a chance if your not living in it. Remember the winter we had in Florida this year. I had to buy a $60 toilet flush valve and I was lucky at that. If you have a cold spell you will be rushing around like a mad man trying to winterize. The vacuum won't blow enough water out of the lines. Get a air compressor that will give you at least 60 psi with volume.
Jo
Found a new trick to the water hose freezing. My trailer life magazine had an article about fresh water hoses and the distance we park from most hookups. The guy took his fresh water hose and cut it at five foot and two ten foot lengths. This kept him from running all that hot water from the sun through the hose everytime he wanted cold water.
So I cut mine at ten foot and put new ends on both pieces and can hook both together if I need more hose. I then wrapped the ten foot section with rubber pipe insulation and it keeps from freezing. The other night it got down to 19 degrees here in Central California for several hours and it's been in the 20's everynight since and it hasn't froze yet. I bought the repair connectors at Home Depot but if you do make sure you buy the brass ones and not the plastic.