The end of the universe is another one of those questions that's fairly fun and/or unnerving to contemplate, depending on how one looks at those things. I'm going with the latter camp, but it's still interesting for me (I had to put something beside unnerving just to make it sound less assertive; I'm not sure exactly who thinks this is the most hilariously funny subject imaginable). There are myriad things that could happen to humanity before the universe makes any serious progression in its lifetime, if said progression ends up noticeable at all. Orders of magnitude are thrown around like... well, I can't think of anything to match how much they're being thrown around. The total stabilization of one system is estimated to take 10^10^26 years. I didn't even want to type out 26 zeros because typing one more or less would add/subtract most of that order of magnitude of orders of magnitude. I don't know how the maker(s) of the theory(ies) would feel about getting it that wrong.
Any possible end of the universe would take orders of magnitude so great relative to studies now just because it would be the culmination of all the other numbers, in a sense. Considering what the Earth faces in the coming centuries, never mind when the sun will unload in the coming billions of years, Earth-born intelligence has some ridiculous obstacles to overcome to be around in 10^50 years (as a number I'm assuming here could only be survived by a sentience if it wouldn't destroy itself and had substantial portions of reality on a leash, at very least). If terrestrial sentience survives the wrath of the sun, I wouldn't actually be surprised if it were hanging on by more than just an outpost on some other planet in the solar system. It could also be completely impossible.
Determining the fate of the universe probably requires a complete understanding of how it works. So far, we've received a lot of feedback that does and doesn't make sense with theories we have right now. Of course, things that don't make sense are just as much part of the universe as things that do, or at least that sounds like a good idea. If dark matter makes up most of the known universe, and if there might be a nonzero cos. constant (or something along those lines), then there is a lot of explaining to do before predictions about what happens next carry some serious weight, even in the theoretical realm. That's basically why I wrote hardly anything about actual end-theory of the page; we don't actually know what most of the universe we even know about is doing.