What makes you think it's the temperature, Nat? Personally, I haven't noticed this to be a plant sensitive to low temperatures, and it is listed as a 'cool' plant in Liddle's temperature tolerances list.

Are you sure it's not just being sensitive about your watering schedule during these off season months?

Here is a link that might be useful: Temperature Tolerances

If anything this one is sensitive to hot temperatures as my plant usually gets some yellow leaves in the summer. I try to grow my plant moist as well because too dry causes problems.
One thing you have to keep in mind when growing in a seasonal climate is to keep the availability of light and moisture in balance. Having a soggy plant in dim light during the winter months is a bad idea. I am not sure how you have been growing your plants but I just want to make sure you know what often causes problems. Is it fairly bright in your area in the winter but with lower temperatures or does it get gloomy like Canada's winters?

Mike

i have only watered once this winter and the plants look happy with that, but low light levels as well the roots like nice and healthy?