Absolutely, I'm a Canadian and I've worked on pipeline...

Absolutely, I'm a Canadian and I've worked on pipeline construction around that area. Trans Canada Pipeline mainline route goes through northern Ontario.
Lots of the places sit dormant in the summer and get opened up in winter as that's the best access. As for cold the contractors are set up for cold weather. They love cold weather in Nov,as this pus a good freeze in the ground and opens the terrain up. In Oz you learn to work in the heat and in Canada you gear up for cold. Snow doesn't stop work. You might miss a day or two on heavy snow, but as soon as you can run dozer down the access site and clean the work area its right back at it.
Worked in both places