the sci fi setting that I made up doesn't have ftl, spaceships take thousands of years to move between systems and are all big self sufficient hulks, then they take thousands of years to terraform and colonise planets, leaving systems largely isolated from each other, regions of the galaxy are controlled by different empires and factions but "control" is used rather loosely since it can take a million years for a message to go through the entire empire, so a central power responding quickly responding to anything is basically impossible, people would also live a lot longer though, living 500-1000 years would be pretty normal, and you could be put in cryosleep, where you could also spend thousands of years, it would take a long time for anything to happen but people would also be alive for a long time so it sort of balances out, it would still mean though that systems are basically all self governing and can't really rely on help coming from the outside if something dramatic happens