What does it mean to be truly Immortal? If your body is everlasting but your mind is not, is it worthwhile to have a lifespan that exceeds the Universe's?

Philosophical questions aside, the former princesses of a long-dead land find themselves trapped in an endless void. With nothing to do but wait, how will they fare with the countless eons ahead of them?

Basically, think Waiting for Godot... with ponies... in space. (Don't bother to ask how they're able to talk, though.)