I haven't comparison shopped for netting in quite some time. When I built my first pen, I bought netting from Seattle Marine, and it is still holding up really well. As I recall, the price was good, and the quality was fantastic.
A huge factor for me was UV resistance. I live in an area where the UV radiation is extremely strong, so it eats up anything plastic outside in a hurry. Zip ties fail prematurely, bungee cords degrade quickly, plastic lawn furniture gets brittle. Even wood doesn't last as long here, and wood finishes -- pfffft!!! So I looked for netting that was made to be highly UV resistant and super-durable, and I was willing to pay more if I had to in order to get that in my netting. I'd already had sunshade fabric disintegrate over the dog pens... needed that to not happen over the bird pens
(Fortunately, the dogs did not fly out.)
I don't know about the level of UV in North Dakota (presumably less than here), but your temperature extremes may pose durability issues for plastic and synthetic-type materials... I don't know. Just seems as though they might be challenged more with the extreme cold?
So that's more questions for you to ask as you are shopping for netting.
Also, I remember looking into the question of snow loading on the netting, too. Depends on the size of the netting openings and the diameter of the netting material as well as the strength of the netting material. Smaller openings = more surface area = more snow weight on the netting, ditto for wider (thicker) strands of netting. But wider may be stronger, so there's offsetting factors... Smaller openings mean less tweety birds sneaking into the pen, stealing food and leaving avian viruses in their droppings, so that's a trade-off to think about, too.
Here's a link to the netting department at Seattle Marine. They have a huge variety of products and sizes of netting.
http://www.seamarnets.com/
Let us know what you figure out -- current info on netting is always helpful