I always assumed (not a spoiler because it hasn’t come from Gilligan, though Bryan Cranston has said it was his assumption) that the series would end with Walt’s death.
As far as I’m aware, nobody from AMC or the show’s production has said anything about when the last half of the season would air. People assume, naturally, that it’s going to air next summer, but there’s not much to support that assumption.
On the other hand, they’ll be shooting the final eight episodes this winter, which is several months earlier than they’ve shot their past seasons. With that in mind, I’m holding out hope that we’ll see the beginning of the end sometime this spring.
We’ve all assumed that. It seems almost a given. But the quote I read said that Gilligan said something to the effect that “now we just have too much story to tell.” However you slice it, our answer will be a long time coming.