PJ,
You can buy tank heaters for the holding tanks, one of my cousins has them on his TT, they came from the factory but are also available as an add on. Try this link;

http://www.campingworld.com/browse/s...H&tcode=37

If that doesn't work go to www.campingworld.com and type in Tank Heaters and it will come up. I know he has camped down to around 0 degrees and was still able to dump his tanks when the time came. Also when he is staying anywhere for and extended length of time he uses PVC rather than a reqular sewer hose, to eliminate the freezing hose problem.

Aaron 8)