Where in the NWT? Mountain hunt or tundra?
I think it depends on what sort of weather you expect. If you are going to be in Rain/shitty weather for more then 50% of the time, then I would just wear the Yukon pants full time. If you'd prefer to only throw on the rain gear over top of your regular hunting gear, when absolutely necessary, then I would pack the lightest pants available.
The farthest north I've hunted was just South of the North West Territory border, and in late August I wore the Yukon pants full time.
Jacket is easier to take on/off to regulate heat. But if you'll be in it more then 50% of the time, I'd still take the Yukon, if less then that, something lighter. Part of this decision is how hot you operate at and how willing you are to take gear on/off to regulate your body temp.