I remember Schwarzenegger declaring a state emergency once because max temperatures dropped to below freezing one day. Heavy stuff! I couldn’t even wear a t-shirt to work!It never ceases to surprise me what kind of "houses" with no insulation to speak of are acceptable and even standard in many parts of the world. If it's cold inside when there's -30-40C outside, there's something wrong with your house. If it's cold inside when it gets barely below zero you should check if you in fact have walls and such instead of just imaginary house.
The foundation of my house would probably crack with -30C temps...