I have no choice about a winter coat. I will just buy one from a maternity store, they aren't really that expensive and if you want you can always sell it or donate it after you're done with it. (unless you plan on more kids)
I have one from my sister, she wore it last year when she was pregnant. It's kind of big but I'll wear it until I get my own.
If you live in a climate that gets a cold or snowy winter I would just buy one.