A lot of the equipment suitable for the Great Divide Trail is similar to what you’d bring on the Pacific Crest Trail, so for research sake you might want to google a few Pacific Crest Trail 2018 gear lists as they’re easier to find.
I haven’t hiked it yet but I’d recommend a warmer sleeping bag, a synthetic jacket and perhaps more durable shoes (still shoes–not boots) compared to the Pacific Crest Trail. However, surveys have said people on the Pacific Crest Trail wish they had a warmer sleeping bag, so perhaps a -15c is suitable for both.
The reason I’ve added so much camera equipment is because I’ve had a lot of bad luck with travelling and I thought if my plans get ruined here, I’ll have a lot of camera equipment on me to take photographs somewhere else in Canada. If you remove a lot of this equipment, you’ll find the base weight isn’t too bad. That said, this particular hike is meant to be particularly scenic so I’ve sacrificed a few items to bring camera equipment. You can sacrifice even more, for example slightly thinner clothes, no pillow, a smaller sleeping pad, etc.
I own all of the items mentioned, so if you have any questions, feel free to ask :).