Try finding an OR Chaos or Perch belay parka if you really feel like you need the extra layer. They're usually cheap on the resale market, or on sale, and have all of the good features you want (two way zippers, internal waterbottle/glove pockets, helmet compatible hood).
It's supposed to be cold in the Canadian Rockies this winter. It has been hitting -5oC already in the valleys which certainly bodes well. There's not a lot of snow and ice yet though.
I just wouldn't bother with reservations. There are plenty of places to bivi that aren't on the trail, and you always have the option of descending the south face to the hut.
The National Park is going to extract a healthy fee for potentially staying in the park and there will be no one checking permits.
Outside of Frank Jourdan's epic soloing binge, has anyone had a better few months in the Rockies?
Jesus, Marc. Leave some adventure for the rest of us.
Also, your writing has improved by leaps and bounds. The Emperor Face write-up was phenomenal.