When we lived in South Texas, we never winterized the Southwind, and sometimes the temp would get down to the upper 20s overnight. But then we moved to Denver. Even tho' I emptied the water, it got so cold that I had a $2000.00 plumbing bill come spring. Best that you winterize before the freeze hits, since RV plumbing isn't all that great to begin with. I've found we can still use the RV on a nice day, by flushing the toilet with a gallon jug of water and drinking bottled water (or beer). I just empty the black water tank afterwards and add some antifreeze. I've had no problem with the pipes to the black water tank.