I don't think season finales should be plotted based on "How do we top the last one?" That tends to lead to increasingly more ridiculous and over-the-top finales (see modern Doctor Who
for a classic illustration). If a season finale really stands out as a special event, it's because it came by that power honestly, as a natural evolution of the story arcs at that point. If you try to force the next season's story arcs into an artificial climax just to try to top what came before, it won't work as well and it'll cheapen both finales. So it's best not to try -- just to let the really big finale stand as the high point it was and not try to compete with it. Look at Star Trek: TNG
. After "The Best of Both Worlds," they did continue doing cliffhanger finales every season, but none of those other finales tried to tell a story as massive and cataclysmic as BoBW did.