Besides in fairytales there's often a lot that can be read into they "all lived happily ever after". Many a fine tale has come out of the premise, well actually they didn't. So what could come out of your stories that have officially ended happily? Could you look at what happened if that "ever after" was nowhere near as long as the characters anticipated?
So happy ever afters can be what you make them to be. And then leave your characters to get on with them...