Is the Sun an efficient producer of energy via nuclear fusion?
While humanity may be years away from commercializing nuclear fusion power, the Sun has been doing it for a while now (and for free!). The Sun is the most efficient generator of nuclear power in our solar system. Inside the Sun, nuclear reactions are happening at a seemingly impossible rate. Hide your kids and hide your wife though, because eventually the Sun is going to run out of Hydrogen and will no longer be able to produce these reactions. When this happens, about 5 billion years from now, will humanity have come up with a way to circumvent the destruction of our society that would come as a result? It took us less than 2000 years to get to sliced bread, so I’m confident we’ll come up with something.
The Garrett Nondorf 
I really liked the link to the video you provided, though it’s an eerie thing to think about! As you said though, we’ve got a couple billion years to figure out a way to escape the inevitable destruction. There have been quite a few theories that have been proposed for basically re-igniting the Sun if its fuel tank is close to empty to prevent this, and though they’re interesting to think about I doubt a lot of them, if not all methods proposed so far, are plausible enough to do.
It is also interesting to consider whether or not the human race will even survive another 5 billion years. Countless of different species on our planet have gone extinct over the life of our Earth, and in much less time than 5 billion years. It would not surprise me if a catastrophic event were to wipe out the human race before the Sun dies out. After all, 5 billion years is a very long time.