Like Joe I work in vry coold weather all the time. We even run a Fine Focus Snow and Ice Workshop. All the advice you have gotten is good, you just need to see what works for you.

I like Joe, much prefer natural fibers for the most part and add layer after layer. I also make sure that one or more of my outside layers is well populated with inner pockets where I can stash film and lenses as I stage them for use. One of the tricks is to gradually change the temperature, either up or down, of your equipoment and film untilyou reach the outside temperature to avoid condensation.

You also need to know what sort of equipment will behave bettr or worse in extreme cold. For example, wood v. metal tripods. Additionally, some years ago I found out the hard way that BOSS Screens behave as badly in extreme cold as they do in extreme heat. In the case of cold they develop styrations working in from the corners. There are also isolated reports of some types of carbon fiber unraveling in extreme cold.

Finally, make sure you can operate your camera controls with gloves or mittens.