I love this subject! I have made some interesting attempts to solve this problem.
Here is a great Idea from a creative lady and the best part is you can wear it front or back, and make it yourself with minimal sewing skills.
Sarah's Poncho
I have also made a
podegi, or Korean blanket So then we both dress normal winter and wear a good hat and I wear a scarf and maybe "sleeves" from an old sweater or coat.
I am going to see if I can attach a photo to show you the solutions that worked for us. Let us know how you figure this out!