Hey, Michelle and Ann - how are ya? We met at the 2011 rally in Lancaster. We could do that, too. Thanks for the reminder!
jimcol - We saw others do that during a Winter in MO. Not a good thing, IMHO. Folks had freeze-up right up the sewer line into the rig. Not pretty. We never leave our grays (or black, of course) open. If you drip a faucet w/o leaving a tank open, then there's the possibility of overflow. Saw that happen, too. I know a lot of folks leave the gray open, but these are risks we don't want to take. To each their own, but thanks for your thoughts.
