Regarding good examples of post-apo, I think battlestar galactica counts. Cylons attack and kill everyone in nuclear winter, only a handful of civilian ships and a military one, a relic that was turned into a museum, make it out. There's like 3000 remaining people in total. For most of it (season 1 at least), the conflicts come from trying to make something out of this situation and racing against the clock. The military ship takes command but some people resent that because the military gave themselves that authority, but they also make things run (although because the main characters are on that military ship it necessarily endears them to us). A prison ship was part of the convoy and now you have the question, they're criminals, but they're also the only survivors of humanity. A lot of "picking between bad and worse" decisions have to be made. For most of it the cylons aren't even that prevalent. In fact in cannon they're more of a boogeyman and most people don't initially believe it. Apparently because of the writers' strike that happened near the end of the show the fourth season is weaker lol.