Really think through what the necessities are when you are travelling to Yellowknife and put them in your carry on luggage and wear some of it.
Our hold luggage was "lost" we had travelled from Australia where it was +28/82 degrees to Yellowknife were it was -28/-18 degrees. All of our cold weather gear was in our luggage.
I would have thought that it was just our bad luck but there were quite a few people on the same plane who experienced the same thing. We met another guy who had flown in the day before and had his luggage lost, he got it back the next day. We met a couple who still didn't have their luggage 5 days later. Some of the locals who have heard our story are not surprised. So far it's been 2 days for us. They know where it is (Calgary), they just can't get it here (I don't know why).
I had no gloves, hat, thermals, boots etc so had to rent them here. Luckily there are places to rent gear, especially if you are doing a tour. And I found this post on renting clothes if you don't have a tour booked ykonline.ca/where-to-rent-winter-clothing-in…
So as I said in my first sentence, pack or wear the necessities, there seems to be a higher chance of you not getting your luggage than on other flights. I'm not complaining about the airline (or even mentioning it) because I really only want to make sure you are prepapred.