When the big bad is down for the count, and all those issues have been resolved, fast forward. Keep going till a decade is gone.
Take it back to the beginning, somewhere that means something, be it a classroom, a station or a family home.
First show the new, children running about, then show off the older old, let us see that time has passed. Past friends are now families, they married their high school sweet hearts, of course, no doubt.
Then reference events, characters and anything else that couldn’t happen to share this spot. Let the dead become names, let the events become memories, just let everybody know that no one has been left behind, even in spirit.
Finally have those children speak. Let them be similar, let them be different, let them look like Chimeras of their parents, let them carry things on.
The perfect ending for when the money dries up.