We ordered Ziggie a custom made coat. I since it was made to his measurements there was no worry about fit issues. He has worn it for three winters-nearly 24/7-he wears it in the house and sleeps in it too, and it has held up extremely well. We plan to buy a new one this winter (just so he doesn't have to "suffer" when we was it every week or so).
This is the Etsy store we ordered from:
www.etsy.com/shop/warmwags. If the link doesn't work, go to etsy.com and search warmwags (one word). Her prices are really good, in my opinion, especially since they are hand made, made to your dog's measurements, and she will customize colors, etc. if you want it customized, just message her before you order so you can get an accurate price quote for what you want.