Are you ready for snow? At that altitude in July you will be dealing with snow on the ground, maybe snow in the air. Is your foot gear up to hiking in snow in steep places?

Personally, I would have along a real down coat, something with at-least 8 ounces of 650 down AND AN INSULATED HOOD. At 11,000 feet in a wind, 27 degrees is serious. But then I always go over prepared and warm clothes are the most important thing I carry.

Pika has direct experience which is important, BUT Pika is as tough as a boiled owl, are you? Seriously, conditioning is critical at that altitude, both muscular and adapting. Are you coming up from sea-level? Your body and its ability to keep you warm will not be able to deal well with the lowered oxygen for a couple weeks. You may shiver a lot.

Be sure your shell layers are big enough to go over your insulation, because you will need the extra warmth of wearing everything you got.
Jim