Here are a pair of boots that you never thought you'd see me in, but here I am. They are Unisa brand, model name unknown, and they have right at a 4 inch heel. Believe it or don't, I didn't measure any other dimensions, so I couldn't tell you what they are. They are substantial block heels, obviously. The uppers are made of a faux suede material, and do not have any stiffness to them above the part that actually goes around the foot. In other words, they fold up easily.
I have been reluctant in the past to even try higher than above the knee because my legs are so short that I don't need any more help dividing them up visually. That, and the very physical fact that what is a thigh boot for normal people is crotch high for me. I am pretty sure that the instant pair were intended to be over-the-knee, but on me they are thigh-ish. Not only that, they actually fit in every dimension, unless I were going for a stretch-tite look.
It was a cold and blustery day on their maiden voyage, and I was glad to have the extra layer. I have no idea what they would be like in warmer weather, and I doubt I'll ever find out. More images are presented on my Melrose Plant thread in the Guys section.