While Amazon pulled the plug on The Expanse beyond season 6 that will come next year, I think that'll be a good time to wrap it up, few hard sci-fi series ever got that many years and I'm glad if they go out with a bang. S01 was good and gradually built up toward a great S03, and new chapter S04 is also building toward an epic S05-S06.
As we evidently move toward extraterrestrials, it's becoming harder to balance the shows local realism and there are budget constrains too heading into alien territory (just a guess, did not even watch trailer). It's a story of humans and humanity, and as long as we get like 16 last episodes Sopranos / BoJack style, it'll finish on a high note.
Enjoy S05 in the meantime, it's dropping 3 episodes on Wednesday than weekly Expanse, I'll take the impatience over binge watching I couldn't resist namsayin. Also, now being cancelled twice, the series made a bit of a history.