I have experience with the Nokia Powersaw boots. I've also had similar versions from Husqvarna.
Tough as nails. I think forestry work is about as hard as you can get on a pair of rubber boots and these really do the job. And Newfoundland will be hard on rubber boots.
I just checked my son's pair and the 44 is 11 in US sizing (as per the chart you posted).
If you plan to put a liner in, you might want a 1/2 to 1 size larger. I usually get a bit larger for a footbed insole (the ones from Two Tracks would be deluxe). Heavy wool sox with a liner sock snug the boot up nicely.
If you just used the Schnees without a footbed insole, a 1/2 size might suffice.
It's tough to order footwear from a catalog.