Does your car turning on, under theses conditions?
Keep in mind that frost bite warnings are for exposed skin. When the actual temperature plus the wind chill factored together amounts to -20C iirc or more you have frost bite warnings.
I take two precautions when the actual temperatures are -15C or more and plug my battery maintainer in to keep my gel cell battery topped up and if it the actual temperature gets to -20C or more I also turn on my engine block heater for a couple of hours or more before I need to start the car.
With my older car the use of the block heater was all that was needed but the newer car I have has all kinds of electronic crap which causes a ghost drain on a battery especially as I do not drive as much as before so the need to keep the battery topped up.
On older cars I expected a battery to last about 5 years before needing replacement. I have no idea how long the gel cell battery with a battery maintainer will last.
Sorry for the long explanation but there it is. Long story short, I expect a car to start set up like that at -35C or more and it is in an unheated garage sheltered from the wind.
I would not want another diesel vehicle again because they are even worse to baby through very cold weather.
Bob