Last night was 2 degress celsous and it is only autum not winter :icon_eek: i expect to drop way more when winter comes. i hope that is not to low of a tempHow cold does it get in the winter where you are?
CO2 production by yeast will generally slow down as temperature goes down. It may get to the point where yeast metabolism stops completely (or they die off), and you will no longer get any CO2 production.