Ugh, I feel your pain. I have a 12-inch calf and wear size 6 and am 5'2".
The best route is probably to have a custom-made pair. The two main companies for this are Ted and Muffy (formerly Duo Boots), and Poppy Barley. I also recently stumbled across another one, TLS (the Leather Shop), but theirs are more expensive, presumably because they also make a custom last for your foot. I am currently saving up for a custom pair.
You could try the Solemani Gabi:
https://www.amazon.com/Soleman.....1?_encodin
These were a perfect fit for my calf, but I found them too large in the ankle, so the overall look was disproportionate. I returned them because I didn't like how large the ankle looked. But the fit and quality were both good. I wish they made more styles.
It is very frustrating. When I find the rare boot that fits in the calf (and I mean RARE), the shaft is too high, grr. The only pair of knee-high boots I have found that had the correct shaft height were the Gabi (mentioned above) and the La Canadienne Stephanie (which comes only in black; and the calf was still a little too large, though close).
Are you open to black or other colors, or to over-the-knee boots? I recently bought a pair of Cole Haan over-the-knee boots that are a very nice fit in the calf. The shaft comes up just a couple of inches above the knee, very nice if you are a short person. They come in black and gray.