This can help to stay warm if you go outside and it is 10 below (for a short time layers..(cheap)

[The Velveteen Ocelot]

7. My bathrobe and fuzzy slippers are enough for a few minutes

to go out and refill the bird feeder. For longer than that one definitely needs a coat. But I'm not sure you need as many clothes as you list unless you're going to be out for quite a long time. I don't think I could even move if I wore that many layers. For normal errand running in this weather (it's -15 this morning) I wear jeans or chinos, wool socks, a pair of lined Crocs (yes, they're hideous), a turtleneck, a sweatshirt or a sweater, a hooded winter coat, a scarf and gloves - that's plenty, especially if I'm in and out of a car or buildings. If I had to be outside for hours, then I'd probably also wear long underwear, high boots, and a warm hat. Layers will keep you warmer, but you don't want to wear so many clothes that you overheat and get sweaty - that just makes things worse. The most important thing is to cover exposed skin if it is very windy, because of the danger of frostbite.