A rapture to the end of time story, kind of like "The Last Question" but not

Question

I am trying to find a story I read a few years ago that involves

• young girl on Earth who accepts an invitation to leave the planet shortly before its doom in a "rapture" style event where all humanity is simultaneously given the choice.

• once she accepts, girl joins the consciousness that saved her and is basically uploaded into a cosmic computer of sorts. This network of minds spans galaxies.

• they can go active or dormant, allowing them to experience the universe in realtime or timelapse along with the billions of other saved minds (earthly and non-earthly). The girl and her "savior" synchronize their awake states so that they can perceive their time together in real-time, but to an observer they might only speak one syllable every 1000 years (this is a paraphrase, not necessarily how it's stated in the story)

• something starts gobbling up the distributed nodes that the saved minds occupy

• just before the end of the universe, the girl and her companion get abducted by this unknown thing and it turns out that

this thing that the "saved" have been running from over the span of time is actually trying to save them from the heat death of the universe, they get pulled into another reality.

I sadly can't recall when it was written, just that I came across it about 4 years ago.

Answer 1

This is Utriusque Cosmi by Robert Charles Wilson.
You can read the full story online here, courtesy of Clarkesworld Magazine.

Humanity is offered a choice;

“The world won’t last much longer,” Erasmus said in a low and mournful voice. “You can stay here, or you can come with me. But choose quick, Carlotta, because the mantle’s come unstable and the continents are starting to slip.”

and gets uploaded into a sort of galactic consciousness;

The plain wasn’t “real,” of course, not the way I was accustomed to things being real. It was a virtual place, and all of us were wearing virtual bodies, though we didn’t understand that fact immediately. We kept on being what we expected ourselves to be—we even wore the clothes we’d worn when we were raptured up. I remember looking down at the pair of greasy second-hand Reeboks I’d found at the Commanche Drop Goodwill store, thinking: in Heaven? Really?

The protagonist uses slow-time ("saccading") to survive well beyond the rest of the human race;

Apparently, it wasn’t necessary to “exist” continuously from one moment to the next. You could ask the Fleet to turn you off for a day or a week, then turn you on again. Any moment of active perception was called a saccade, and you could space your saccades as far apart as you liked. Want to live a thousand years? Do it by living one second out of every million that passes. Of course, it wouldn’t feel like a thousand years, subjectively; but a thousand years would flow by before you aged much. That’s basically what the Elders were doing.

And there's an enemy gobbling up the universe;

“Last I checked,” Erasmus said (which would have been about a thousand years ago, realtime), “the Fleet theorized that the Enemy is made of dark matter.” (Strange stuff that hovers around galaxies, invisibly—it doesn’t matter, girl; take my word for it; you’ll understand it one day.) “They’re not material objects so much as processes—parasitical protocols played out in dark matter clouds. Apparently, they can manipulate quantum events we don’t even see.”