How naive. Oh, don’t get me wrong, the “all we have is now” part is spot on. By all means, go play with your kids. But the last three, remotely bleak assumptions are pure technical hubris. If history shows us anything, it is that what we consider the “whole universe” at any given time is nowhere close to any such thing.
The current disposition on the extent of universe is embodied the cosmological principal; at the level of galaxy clusters, everything everywhere else out to infinity looks just like it does here; a presumption which requires that the Big Bang comprises the entirety of the (at least potentially) infinite universe. Poppycock.
Think of it this way. Every last physical phenomenon ever discovered turned out to have two immutable qualities. One — it was finite in extent. And two, there were more examples of that class of phenomenon scattered all over hell and gone.
Thus, you can bet your last quatloo that the Big Bang is a local phenomenon (in a universe chock full of ’em) that lumps together somewhere with a bunch more of ’em to make even bigger stuff. That’s the picture.
So all the stuff around here may well fall into black holes, but we have no idea what may happen to those black holes later, if they get to a certain size (an blow up?), or fall into a region where some larger energetic phenomenon acts on them (and they form stable orbits around each other) or if they fall back into the grasp of the same phenomenon that spewed us all out 14 billion light years ago.
So lets quit thinking that we have any idea about what happens 10 ^ 15 years from now, and go play with our kids.