@Neko Majin C  
Neko, dude.
 
Not cool. I didn’t want to think about that. I don’t want to think about that.

@Neko Majin C  
Now that I think about it, if Tartarus exists and is easily accessible, why would Elysium not exist? Sure, it would not be as equally accessible, but I am sure a goddess such as Twilight could visit the outskirts of the Elysian Fields and say “hi” to her friends once in a while. Once she sees and understands that her deceased friends are happy and safe, her visits may become fewer and farther between, and then she can move on with her life. Hey, maybe that is where the Map is sending her for the first time, one last time.

Yes, friends die, one by one. And when you are newly immortal, losing the first group of friends you were closest to would be most the difficult hurdle to get over. You do not forget your dead friends, but you do move on. Spike is sill around, he ages differently from ponies, so whenever the last of Twilight’s ten mortal friends—assuming she has not made more by then—dies, he will still be there with Twilight. He may be enormous, but he will still be there. And if Twilight is immortal, that means Cadance is as well. So she will have at least one other pony friend that she has known since childhood, and is around the same age as she is, to be with her for eternity.

in an alternate universe where trixie won and twilight was forced to leave ponyville forever