And one turtleneck, definitely. Take a bulky, hand-knit big black sweater. With the chiffon skirt or a jacket, you can have a tailored mix of masculine and feminine to suit your mood. I always travel with a blanket cashmere scarf, which I can use on the plane as a blanket, use as a warm wrap or throw over the shoulder as a scarf. You can also put it on the bed in your hotel, if you don't like the linens.
Some people are shy about traveling with leather, but it really makes sense.
It's lightweight, like skin on skin, and very comfortable. Great to travel in. I just went to L.A. and back with this wardrobe. It was weightless and warm, and it all fit into a wheeled duffel carry-on bag. All the pieces fit together, and I could layer or shed as the temperature required.