This would also be a good opportunity to implement the "Ironman" game mode where you can't save manually at all.
You just get one autosave which saves at every possible step, basically a "Save State" function like in an emulator, only as real data save to there is no re-loading of earlier states.
If someone dies, he dies. If you misclicked, you misclicked. Oops, missed the day/night horizon by a few pixels and now you have to do a night mission against chryssalids? Well, so be it.