I was surprised at first when I read how close the conclusion is, but it now makes sense to me.
Karder already dominates the Eastern Sister. It makes way more sense for the remaining kingdoms to bend the knee than to fight him. This could easily be wrapped up in a couple of screens (or maybe a few more if Karder gets some sex out of it after all). We know that the Western Sister is much more centralized and tightly ruled by Queen Remy, so we shouldn't expect to continue the "slowly chipping away"-strategy that got us the Eastern Sister. Basically, a significant clash of forces is upon us, whether it is Remy invading the East or Karder invading the West.
This clash wouldn't have to be decisive per se. We could have Remy invade the East, Karder beating her back at signifcant cost, and then a couple of updates where Karder builds up strength, with more side stories, returning LIs etc. I think there is much we would love to see expanded upon, but this risks turning epic fantasy into slice of life.
However, the clash could easily be decisive: Remy leads a significant part of her troops into battle personally, Karder uses his newly acquiring divine power, beats her and takes her captive. The victory celebration follows, and then we have an epilogue teasing the sequel and showing Remy pregnant with Karder's sibling/offspring. I'd hope that Remy will get to prove herself as a significant threat before going down, but I do believe Doorknob can get us to a satisfying conclusion soonish.
When it comes to what is next, I'd certainly want to see more stories playing out in this world. Karder as an older man would be interesting in principle, but would lead to complications with all of the children he has sired. If I had a vote in this, it would probably be for an anthology of shorter stories.