I don't mean to contradict what Doc said, but I live in PA, and the Standard's thin lambskin definitely does not work for me as a winter jacket, even when layered. I understand Todd is using a new variety of lambskin since I bought my Standard, though, so perhaps the newer version is a bit warmer-- but I still wouldn't trust lambskin in bitter cold weather.
For winter use, I would check out US Wings (perhaps cowhide or goatskin for maximum warmth). If you need a custom fit, you could try Magnoli Clothiers, and if money is no object, Tony Nowak, who will build you a jacket that will probably outlive you, and provide you with an amazingly high level of service and personal attention.
But I do agree with the other comments: Todd's jacket is unbeatable for the price and is also one of the most accurate looking Indy jackets you can buy at any price.
Jack