Why does there only have to be one universe? There could be an infinite number of universes out there, all expanding or contracting or exploding or undergoing heat death all at the same time. The fact that we happen to be here, on this planet, in this universe, at this particular instant of time, is simply a cosmic accident. Even as this universe eventually comes to an end, some of the matter and energy from it could interact with matter and energy from one, or two, or countless other universes, eventually collapsing into another cosmic egg, slowly building as it absorbs yet more energy and matter, until finally, billions of years down the road, that one last electron, or one last atom, or one last neutrino, plunges through the event horizon and pushes the egg into another big bang. A new universe is born, comprised of material from countless other universes, like a child with genes from dozens of parents.
And all without any need for sky fairies.