Ashby, this is how we handle it. We have a +/- 30 gal grey tank, +/- 20 gal black tank. We dump two gals of RV antifreeze in the grey, one gal in the black. We run the macerator pump off the grey until it is full, pumps pink out the hose.
We only run the tank heaters when we are underway. I don't know what the heaters draw or what you have for batteries but I assume they do consume some amps. I also should mention we have lots of battery and solar capacity, and heaters on the macerator.
Donic 13, yeah I get the step system, the way its suppose to work anyways. Add cold, moisture and who knows what, things can and do go south. Even under ideal conditions most of us have had bad experiences with the plunger switch, allowing the steps to randomly extend. I haven't checked for a fuse, but pulling it would be a positive cure, I think a simple switch might be easier. Thanks for your thoughts.
Ron, if you are camping at 10,000 ft in October you are considered a Winter Camper in my book...!!!!
Doug