Im not at SAIL but I have been up in Helsinki during winter to operate for a local airline there. I don't think Scandinavian winters are something special, I would more say its easier than central european.
If the snow falls in Arlanda, so what? where is the problem? They are professionals in handling the snow, deicing, getting the airbus computers to work when its cold. Sure, braking action "good" isnt always good, its sometimes medium to poor, but we´re talking about an A320 landing, not Mriya A225 ! Same as the tailwind on "14" in LSZH. 3 knot tail on ATIS; 15 in real. Local specials you need to adapt to....
Its so easy flying up north in the winter in my opinion.
Imagine FCO, 5 cm of snow. They first need to get all deicers from the coffee machine , and every pilot is scared of taxiing on Ice/Snow so the whole airport would breakdown. Same in germany, france etc. its always a surprise that the winter starts in december....
If you have drifted a bit with cars in the alps on snow you know how an aircraft handles and that you need to make smooth inputs and be relaxed and not afraid.
So SAIL pilots are skilled exactly as other pilots. They're for sure doing a great job.