Here's a true coatdress, with a very simple fastening and cut. Don't see why this couldn't be made RTW. It's basically a close-fitting topcoat in a fabric for gowns.
It's pretty, but it looks like a coat and is rather stiff. The American businesswomen and professionals I know who have to dress somewhat formally and have the money to buy nicer clothes usually don't dress like this. They like comfortable separates made out of luxurious fabrics, or sheath dresses, which can be paired with a jacket or a nice cardigan.
Don't forget: Americans in formal environments who make really good money tend to have really long hours: 10- 12-hour days, even all-nighters. Clothing that is layered, can be removed as needed, is breathable, and doesn't wrinkle easily is preferred.
Edited by tailleuse, 13 October 2015 - 01:28 AM.