How do you break them up and/or refresh them? I'm super curious. My idea was to actually make manual breaks when I felt enough time had passed.

Options? Ideas?

Consider how much your group accomplishes in a typical tabletop session.  Usually, there's some sort of sense of having reached a suitable plot-point on which to pause the game.

I take this idea and say that at "suitable plot points" we'll call it a "session" and offer the Refresh and stunt-refresh.  Depending on the pace of the game, that might still be months before it happens.

I just wrapped up the first scene in a Dresden Files game.  Combat is over...  it's a suitable point at which to call it the end of the session.  Either way, there should be some sort of sense of accomplishment (good or bad).