First of all I don't think we will get to see any of these scenarios. I would be more than happy to see new Naruto content but according to what Kishi said, it's not likely. Maybe some novels written by others.
The Uchiha clan is probably in the most questionable condition now out of the current clans. It's more than possible for SasuSaku to have a son so the name would be more likely to be inherited, though it may not be necessary (Naruto's or Inojin's case for example). I do believe the Uchihas won't be extinct, because SasuSaku was meant to be the revival of the clan. There may even be more Uchihas spread across the world, hiding and living secluded.
The Senju clan's state is interesting. Opposed to how big and powerful their clan is, not many Senjus were introduced. Their influence in Konoha is also questionable, because their Will Of Fire and Tsunade seem to be all that's left of them. Konoha Hiden also suggests that they are no longer around. What caused them to disappear is unknown though it would be nice to hear an explanation. With no serious Uchiha threat after Madara's "death", their clan should have risen even more, any notable events that led to their supposed extinction should have already been mentioned in the manga. No wish to start an argument, but the lack of Senju storyline only seems to strengthen the fact that Kishi made them false main stars.
The Uzumaki clan is not threatened in any way. With Boruto and Himawari, the clan's revival is more than guaranteed. It was confirmed that the clan has survivors spread across the world, and if Naruto's descendants become a well-organized clan, then remaining survivors will probably merge with it. They will even have Hyūga blood in their veins, which just strengthens them.