I've decided to bring my standalone camera. I'd lost the charger for it, so I didn't think I'd be able to bring it, but I figured out how to charge it with my RC hobby charger (I didn't even know it had a Lithium Ion setting). I'll have my phone, but it'll probably stay turned off in my pack the whole time. It's way heavier than the phone, but hopefully it'll be worth it for the better pictures. Not to mention, the battery life on the phone is atrocious.

ETA: By the way, the list of things I need to sleep with to keep them from getting too cold keeps growing. My phone and camera batteries, water bottle, filter.