A tongue-in-cheek way to address this would be to put a 1 cm line on the map and label it "1 mile." (intentionally mixing metric and imperial because why not)
Also, I agree that Larian's environments are too beautiful to cover in fog.
If the entire game takes place in midday, what if there was a symbolic way of keeping time? You know how in Minecraft you can make that clock? You can be deep beneath the surface and still it will tell you if it is day or night. Maybe having a more symbolic clock d/n cycle could get us a sense of time without forcing too much rework around the idea of a d/n cycle? And then that combined with symbolic distance on a map could hammer home the idea that the world is much bigger to our characters than it is to us.
