Material is not as important as cut. Be sure the coat fits in a way that air does not blow down your neck or up your back. My ski coat is synthetic w/ fleece inside. It has a drawstring that cinches the bottom tight, a cinch in the middle and a tall neck. TOASTY!
My suit coat is long, black wool. It is long enough that nothing gets in from below and the collar is designed to keep my neck warm.
My camping/ work coat is fire hose material w/ fleece inside. it is heavier than the other two coats put together. But the collar allows my neck to get cold. I wish it zipped all the way up.
This coat looks toasty warm and inexpensive -
86111 - Duluth Trading Company