Couple of thoughts:
Fuel - the lower the temps, the harder it is to get a gas stove going. Having said that, I've used isobutane (I think that's what the combo butane/propane mixture is called) on lots of "summer" glacier climbs - not unlike your trip - and it works OK. Sometimes I've needed to put the cannister inside my jacket to warm it up. Sometimes the piezoelectric lighter doesn't work, so be prepared to light it by hand. I always pack a couple of cigarette lighters as well as wooden safety matches. But, those trips were only 1-3 days - relatively short. For something like your adventure, I'd use an MSR Whisperlite, a liquid fuel stove. Some of the models will burn nearly any flammable liquid.
Bear cannisters - independent of whatever the USFS/UPS regs are - you might consider some form of protection. A year or two ago I was at the Portal on the first day the road was passible all the way to the store, getting ready for a dayhike up to Trail Camp, and made a comment to the fellow parked beside me that we probably didn't need to worry about using the bear lockers and clean out vehicles since it was so early. He told me he worked in the backcountry all winter long, and frequently saw active bears, so ... I guess not all of them hibernate. I put my stuff in the bear locker...
Finally - an observation or two on pads. Am pretty sure yours has a slow leak, and I'd replace it. They shouldn't lose air overnight like that. Also - and you (and others) may be highly skeptical of this, but ... several years ago a mountaineer with lots more experience than I told me you sleep warmer if you put the air mattress down first, then the closed foam and then your bag. It seemed quite counterintuitive, but ... this guy had quite literally been to the ends of the earth, so I kept my mouth shut, and tried it. I found he was right. YMMV.
