Let me start my comments by saying I am a NaruSaku fan, but I'm going to be unbiased in my reply. Given Kishi uses Asian mythology and follows the clan hierarchy/dynamics there is a chance for this to happen, but only on the back end.
Under most normal circumstances, a heir to a clan is set up in an arranged marriage with someone within the clan who has been determined to be a preferable mate and can strengthen the bloodline.
However, in my studies of Asian history, there have been extreme instances where someone from another noble family has married into a clan. Minato's family were likely fodder and Naruto's clan is extinct, however, his father was Hokage. Given that bit of information, plus the fact he's likely Hokage after the war, I think if Kishi wanted to make this pairing happen it could realistically do so.
All that said, if Kishi follows his past writing trademarks, I don't see this pairing happening or the Sakura pairing.
