I read this years ago. If I had to say how it was turned in to a TV series in one word I’d say disappointingly. I’m surprised anyone dared to try and depict the environment in a TV show but I think done about as well as is possible to do. I stopped watching after an episode which ended with a weird sequence I’m pretty certain isn’t in the book. The TV show has a bunch of stuff about Borlú’s wife which isn’t in the book because book Borlú doesn’t have a wife.
There is at least one real place that has a significant element of The City & The City but I won’t mention it because of what you said about going in to the book cold.