Since Season 2 of "Re:Zero" only covered up to "Arc 4" of the original light novels, there is still plenty more "Re:Zero" left for White Fox to adapt (via Re:Zero Wiki). The most recent arc followed Subaru and Emilia as they attempt to rescue the inhabitants of Sanctuary who are trapped via a mysterious magical barrier.
"Arc 5," where the anime's story is set to pick up, follows Subaru and his allies as they fight to unite the Royal Election Camps in Watergate City in order to defeat the Witch Cultists who have taken control. Whether the anime is expected to adapt just this arc or continue even further into the series is unknown at the moment.
However, fans can be certain that Season 3 will include many of the story elements which define "Re:Zero." In other words, "Re:Zero" will continue its long-held tradition of brutality and psychological torture, as Subaru's Return By Death ability consistently proves itself to be both a blessing and a curse. Any further details, however, are likely being saved for the show's (hopeful) upcoming release.
