I ask this question out of ignorance due to having never lived any length of time in COLD country, like below -10 for weeks at a time.

When people in the house routinely take long, hot, humid showers how do you keep the bathroom from becoming moldy?

Is the answer a big a** bathroom fart fan complete with seatbelts on the toilet? Or keep the window open and risk bad things from the really COLD air (I would presume.)