It depends on weather. October can be stinking cold at 11,000', where you will be camping. If you have the clothes and a warm enough bag you will be ok. You might want to consider using a closed cell foam mattress as a second pad. Two years ago in mid-October, I could not get my feet warm utilizing a BA Insulated Air Core.
Snow is anyone's guess. Once it comes late in the fall, it ain't going anywhere until the spring up high.
