Well, that was dark. I had hoped for a somewhat brighter ending. It's a very well written story, and though it's short, we get a good idea about the characters.
I must say, the end of the universe is something I've found fascinating for a long time, though it is a very depressing idea. I don't know whether you watch Doctor Who
but there's an episode called "Utopia" where they travel towards the end of the universe, to a time when most suns have gone out. There are some survivors who desperately struggle to find a place where they can still live.
It's an unbelievable amount of time away but the thought that one day, everything will end always saddens me.
I liked the theological conversation - or rather, monologue - although I would have had different replies than Sigrid.