You can totally do a far future setting where the descendants of the Redstripe Centurions have been nearly wiped out by their rebellious creations, the humans, and are searching for their brethren on a mythical planet called Earth.
That could work, in a way...
Perhaps the original BSG series is in fact the sequel. Meaning: After the events of nuBSG, the Cylons went back and rebuilt the colonies. Cleaned them up, reconstructed human civilization as best they knew it, and repopulated all twelve worlds. Eventually they forgot that they were Cylons and believed themselves to be human. And in due course, encountered an alien race of robots to which, due to some ancient racial memory, these 'humans' gave the name Cylons. Thus, in BSG-TOS, every human character we see is actually a descendant of humanoid Cylons.