I created a
thread for hot and cold outfits when Seasons was about to be released. Maybe you can find some inspiration there.
Here are a couple of my sims. I don't usually like the jackets with half sleeves for cold wear but sometimes make an exception. There really isn't enough variety with proper jackets. You can always compensate with a warm looking hat and/or gloves. I think almost anything long sleeved can make a decent cold weather outfit especially as they will also use these clothes inside the house. Don't limit your creativity too much :)
https://i.imgur.com/mL09F9I.jpg
