In the previous entry, I mentioned one of the main issues with our above-ground cistern: the short pipe between our house and the water supply freezing. I believe I have found a solution to the problem: heatline. It's like heat tape (electric wire wrapped around a pipe that generates heat to keep it from freezing), except it goes inside the plumbing.
It's quite expensive, but it uses less then half the wattage (~3 watts per foot) of typical heat tapes (~6-12 watts per foot). Given that we currently have to run our generator for a few hours every day in the winter to compensate for the lack of solar gain, it should pay for itself in a season or two.
The second thing we're doing differently this year is insulating our cistern properly. This weekend, we demolished the original shed and started building a new one. Rather than slapping a temporary structure together, we're following comprehensive designs that Tara drafted.
Next weekend we're going to experiment with some insulation we've never used before: blown celluose for the walls, and a do-it-yourself spray foam kit for the roof!