Would adult "short" tall boots be an option?
Failing that, try Shires Moretta boots (Moretta seems to be the name they give all their boots then each style has its own name after that). I've had a quick look and they only have standard width in the children's boots but they have lots of different styles so one of them might suit. I've just bought the Moretta Gianna boots for myself and I've very impressed with them for the price.
I have no idea about recent boots but 20 odd years ago I bought jodhpur boots and leather gaiters for my son. ( English Gaiter Company, if they’re still in business ) He didn’t need wide leg boots but somehow no off-the-peg ones fitted.