Don't forget that you could just flip your map upside down or 90 degrees, who knows if that might help you out. I'd also say go with nature where possible but to be honest I don't worry about this all that much. Maybe when i become adept at popping out maps right and left I will.

All the players I have played with are playing to escape reality, so they wouldn't twinge about anything. As long as I have some sort of explanation, they are good to go - bust out the swords, we have a rescue to accomplish, who cares if we can walk upside down on the ceilings.

Now, if you are writing a book on this, I'd say you better work out your reasons a little more because there will be readers who will go ape nuts over little stuff like that.