I think eventually, Pep will stay with the city football group for a bit and work as a club ambassador. Maybe not right after his current contract but one day.
One thing I've noticed is that the club has been offering it's expertise for a fee to other clubs in implementing growth and other processes to help other clubs grow and then hopefully succeed.
I can see Pep being a part of that. He can be a club ambassador, oversee the entire level of coaching and coaching philosophy throughout the CFG (every club in the group including the first team, the academy (a big draw for him because he's expressed his love for coaching and molding young players), women's team, etc..) and offering coaching expertise, philosophy, etc to other clubs that will undoubtedly pay for that service.
What better way to expand Pep/Cruyff way of football.
I do not believe he will ever coach for another team in a country that he has already managed in. AC Milan is the only team in Italy, I think he possibly has an interest in. After his experience with Bayern where to board is so heavily involved plus the politics that he dealt whilst at Barca will turn him off to the idea of coaching Juve. Inter has a successful coach in Conte. PSG won't be challenging enough for him and I can't see him going to another team in France.
As for the national team, there isn't enough training time available for him to implement his style for any team at that level. So it's tough to say where he will go after City.