CG originally was an amazing product. It was the jacket everyone got if you went to McMurdo. They still sell them. I had one of those, now have something lighter. None of the original stuff is packable per se because too many zipper, integrated hard sell, etc. I do take them up north but that would be in a Red Oxx duffle. Sadly, CG is going the way of the North Face, Patagonia, REI, Filson and many others - more fashion and a lot less function durability.
What you want is what I call a puffy jacket, down, with relatively thin rip stop inner and outer shell. These are everywhere. CG and Arc'teryx are probably the highest quality currently because they still cling to their roots, but NF, Patagonia and seemingly everyone else makes one.
Do match the down fill to your activity. What is warm at temperature can be miserable once you get active - you'll be soggy in no time. If you're going to be out of an urban environment, particularly if you can't get to shelter quickly should the need arise, I'd go higher quality. In the city, it doesn't really matter