There is a podcast run by the german newspaper "Die Zeit" [1] where the concept is that the interview goes on until the guest thinks everything is said. The episodes usually last between 4 and 8 hours. The longest taking 9h 40 minutes.
There is one episode with Ian McEwan that is recoded in english if someone that doesn't speak german is interested. That one just takes 2h so its not really a good example.
[1]https://www.zeit.de/serie/alles-gesagt [2]https://www.zeit.de/gesellschaft/2019-12/ian-mcewan-intervie...