One other comment re: winter hats -
If you're trying to create a setup that will give you maximum protection when it's cold and windy, such as above treeline conditions, you may need to make some minor alterations on your WindStopper (insert preferred brand/model) hat. When it's truly cold, and you're wearing goggles and full-face protection with the hood of your shell cinched around your head, you may find the hat gradually creeping down over your eyes. Not a good place to be, as you pick your way over frozen/rocky terrain trying to maintain your balance in the wind. To avoid this, I made some moderations by increasing the existing tucks in the hat with a sewing machine. Put the hat on, cinch it down, and put on your goggles. If there's still slack between the top of your head and your hat, there's a good chance it will creep forward over your eyes. So, increase the tucks with your sewing machine, a little at a time. It took about 3 adjustments to get mine just right, but now when I put the hat on, adjust the goggles and neck gaiter, I'm confident it will stay put and I can focus on other things.
Kevin