It's really getting cold and should hit freezing tonight.  Our compost system was a simplified version of the Jean Pain Design.  Right now we're still producing plenty of biogas for our needs.  I forsee a possible point of hibernation in the next month or two, but we're going to do everything possible to keep Gertrude and Lawrence chugging along, even if at a slow pace.  Next year we'll add some serious pex tubing into the manure pile and some piping to keep it oxygenated since we have to keep in mind that compost is aerobic, while biodigesting is anaerobic.