Fly To Nepal and buy a fake north face jacket. I saw it made with pure goose down. Cost me about £38 ISH. T-shirt and that is all you need, in fact too much above minus 2
I've got a Montane Icarus insulated jacket which is warm with just a t-shirt unless it's sub zero. For when it's really cold I have a Craghoppers waterproof parka that is unbelievably warm and it looks like it'd be at home on a trek to the North Pole.
My daughter bought me a winter coat 2 years ago. I won’t take it off now until about April.
It seems to have the feathers from about 100 ducks, and pockets I haven’t found yet.
My best coat ever.