I just had this random thought. Let me know if it’s a complete miss.
This thought is to maybe make it so we’re only saving things that have changed since the last autosave. So we have this overlay that has a tile per tile (however map data is organized) of the map. On this overlay each tile is either true or false… Right after a autosave the entire overlay is set to false. Anytime a map tile is changed it is set to true. When the next autosave happened only those tiles that are flagged on the overlay would be saved. I got this idea from incremental backups for computers. 
Well yea, we need to do incremental saves, and it’s totally doable, it’s just a matter of doing it.
Prioritizing savegame performance improvements over new features or bugfixes is a really hard sell.
Also messing with savegames has the potential to break things REALLY badly, which makes people a bit hesitant to work on it.
This issue IS on our radar though, we’ll get to it when we can.
can you make it so we can choose at how many turns/minutes the game autosaves?
I thought there was an option for that, but there isn’t. Yea that should be easy enough to do.
Thanks Kevin, what he said about how often was my next question. 
Also, yeah, I realize futzing with saves has the potential to totally boff the game. With all the other development I understand that it’s not the highest important. If the concept is useful then, I hope you use it eventually.