Let's suppose that by a miracle, humanity survive for trillions (or more orders of magnitudes more) years. Somehow we end up conquering galaxies and we extend extensively across the universe. Even if we have a very firm foothold in hundreds (or thousands) of galaxies, what would we do in the face of the ever dimming stars? Could we survive in a universe without any stars? I don't know what we could do with black holes, but those would be the last "stars" to survive the universe, but even those will eventually disappear from hawking radiation.
And yes, I am also taking into consideration of the "breakdown of matter". Or.. decay of matter? Whatever it is. That's probably far worse than facing eternal coldness, starless skies. Exactly what could we do if we were faced in the situation that our very universe was slowly turning into atomic mush? Is it impossible to do anything about that?
Probably not. Thoughts? I'm curious. This is a question I've been thinking about for a while. Even if there is nothing we could do about our own universe from dying, I still wonder what we would really do? Would humanity just kick back and say "Well, that was fun."? Could there be ways to save humanity even beyond the heat death and the breakdown of the universe?