stay indoors mainly! Are you in the city or countryside. If the former, the general practice is to get in your (necessary) big car in your indoor garage, drive to an underground carpark, then go to work/shop etc, without braving the elements.
Big duvet style coats and lined boots are de rigeur, but you are better buying them there, they might even be on sale as Winter will be 3/4 of the way through, even though Feb/Mar are still very murky. Warmish weather probably won't be happening until late May
All of that said, Canadians know how to do proper deep winter - including fab sports/ events etc, so I'm sure you'll be fine
As for -30, you really notice the cold up to -10 and anything below that doesn't feel that much colder IFKWIM, assuming you're appropriately dressed.
Where my sister used to live it was easily -20 / -30, and the kids were playing outside as much as where I am now where temperatures rarely go below -10.
You will find all the clothes you need there. But, wool underwear. Wool t-shirts, socks, and leggings. Check out this Danish manufacturer: JOHA Their underwear has a cotton inner lining, wool outer, so it is as soft as cotton and as warm as wool.
Ask what people near you do. Here they tend to heat houses/shops to almost unbearable levels and so having thermals and whatnot is a nightmare as you spend all day stripping off and getting dressed again. For us we dress in the same stuff all year and just vary the coat.
Like others have said - good clothing. Buy it there.
Find out if you'll be living somewhere the snow plough goes and if not, learn how to clear your road/access yourself or be ready to drive regardless (like someone else said, life goes on). Driving on snow (with chains of course) is not that difficult once you get the hang of it and learn to recognise different conditions. E.g. beware of snow after a mini thaw (ice under fresh snow) - no grip.
Sometimes you can have these really low temperatures but it really doesn't feel that bad if there is no harsh wind and no humidity. So it can be surprisingly easy to cope with some days, but obviously use your common sense and limit how much time you/DC spend outdoors.
Decent central heating system. If it is electric dependent, find out about power cut situations where you'll be living . Double or triple glazing. As much insulation as you can possible fit in to your loft! A tiled enclosed porch for removal of snow-wear without mess in the house.
It's not unusual to start feeling miserable in the winter too. I found getting myself outside on sunny days really helped.