I really want to buy a rabbit fur coat, but I don't know how to keep warm compared with down.

Fur is not as warm as down jacket. This is because the fabric of down jacket is a kind of material similar to outdoor poncho. It is windproof. Not particularly breathable. You said that your winter weather is only five degrees. It should be no problem to buy one. Wear thermal underwear. Wear a high-necked knitted wool fir with a fur coat. Put on boots below, it's very classy and feminine. Show the beauty of women. Ha ha laugh