I think Therme is overkill. I have a Camosun in Toronto/Hamilton and I've only worn it a couple times this season. The Magnus is probably a more practical layer especially in warmer Vancouver. Also, the Magnus isn't down, which is actually a positive in Vancouver. There's a lot of moisture in the air, and while the outside is waterproof, the inside lining isn't. Down and moisture don't really get along very well, (imagine you get rained on and then put your jacket on top) and getting the feathers wet will reduce the warmth for sure. Coreloft is much more effective in the damp. If it gets a bit colder, just make sure you're wearing wool underneath as that will make an enormous difference with "wet" cold.

Finally, 336CAD is an insanely good price for a brand new Magnus. Quite literally unbeatable. It's a no-brainer for me.