Last year I had my plants outside until mid-November (SE Pa) and when we were about to get our first frost, I brought the collection to the lab, where they resided in 60-something temps. By mid-January, my D. binata & filiformis, which had gone dormant, woke up. This year, due to the move to WNY, I had the plants split up. I had D. binata & filiformis in buckets of minibog put up in the attic, at a window, where it would be cold but not frigid. The idea in mind is that when the photoperiod increases, they will wake up in response to the light. I also have a pot of binata at a window sill. The plants that were at the warmer sill woke up in January, while the ones in the attic woke up in February. Bottom line: it appears that photoperiod is the dominant variable, but temperature is also important.