What I'm seeing is that the ground with fog is brighter than the sky at night. That doesn't seem right, usually the ground forms a silhouette against the night sky. One simple way to achieve that is to make the fog color darker than the sky color at night in your script that handles the day/night cycle in your environment node. Since there's still contrast against the sky it should be possible to see far-off landmarks. If it gets too black, that's why I recommend reducing fog density because that should help with the problem of seeing things that are far away. I also recommend turning off sun scatter in the same script when the sun is down, that's really meant for strong directional lights that can shine through the fog and it won't work well with the moon that can't do that. Capiche?

If you feel comfortable sending me your project I can mess with it and see if I can come up with something I think looks better.