I think people assumed the love route would have around 7 updates because the slave route had 7 updates. And since we are on update 4, that would imply roughly 3 more updates.
But with how the story is progressing I hope we get around 5 more updates. Although that all depends on the length of the updates themselves. I hope for 5 because I don't just want the story to end when we have sex for the first time with Korra, Jinora, and Kuvira. There's a great potential to use Jinora's jealousy, Kuvira's interest, Katara's concern, and more to have interesting sex scenes that go beyond penetration and anal.