Duo Boots had a good solution
This company sold a good selection of ladies boots where each foot size came in 20+ different calf sizes.
In the shops, you couldn't actually walk out of the store with the goods - you bought them and they were delivered to your home - but what they did have was every single size combination (or at least the vast majority of) in the shop.
It wasn't so much of a "Do you have this in size X?" as just a quick measurement and then they came back with your size and/or bracketed: one above, one below. Job done. It wasn't perfect, but a damn sight better than most experiences.