Humanity is already extinct in a sense. Humanity is no longer limited to flesh and bone. I've personally seen flesh and titanium. And more variation is on the way. So humanity as it were, is already extinct.

We (you and me) will go extinct someday. Our bodies were always destined toward this terminus... Perhaps by some miraculous tech, we can someday change form and shed the flesh and bone. Maybe then we'll have a better idea of what we are.

"We could thus imagine, as an extreme case, a technologically highly advanced society, containing many complex structures, some of them far more intricate and intelligent than anything that exists on the planet today — a society which nevertheless lacks any type of being that is conscious or whose welfare has moral significance. In a sense, this would be an uninhabited society. It would be a society of economic miracles and technological awesomeness, with nobody there to benefit. A Disneyland without children."

--Nick Bostrom, Superintelligence: Paths, Dangers, Strategies

It's not a given that anything of value will survive.

C.f. Meditations on Moloch. We are on our way towards exactly that.

http://slatestarcodex.com/2014/07/30/meditations-on-moloch/

That is going to happen, regardless. Even if we figure out all sorts of things, entropy is still the final boss of the universe.

I'd imagine that an intelligent life form surviving until the very end of the universe would be suffering a long and lonely death. As the heat death of the universe happens, over billions of years, there would be very little of anything left but isolation - for a very, very long time.

I'd hate to be the last one standing without enough usable energy left to even extinguish your own life force. I don't find that appealing, not even a little.

What about the hope that fundamental physics breakthroughs enable escaping that outcome?

Or, if that doesn't pan out, what if your goal is to be the last one standing for the chance to see if something else happens next? New big bang? Simulation ends and you get loaded into the next as your prize? You won't know unless you try to find out!

We are pretty sure about that entropy thing. I'm not sure I'd bet against it. It'd also be a very, very long wait. I imagine any more immediate death is preferable.

It's going to be cold and lonely when the lights go out. This is the price we pay for an ever expanding universe.

I do admire your optimism, however.

Look, if the final heat death of the universe is what kills us then that is fine. We'll have done as well as we could.

Okay. It's not fine, but it is the best we're at all likely to get.

At the moment and for the foreseeable future we are at a much greater risk of extincting ourselves.

The trick is to not do it at all.

It does us no good to avoid causing our own extinction if it's then caused by something else.