I zipped my map files and uploaded them to my google drive: https://drive.google.com/file/d/10-y...ew?usp=sharing
You could scale it down if it's still too large, however you would need to do some manual editing of coastlines and mounain passes to avoid CTD's, bugs and AI pathfinding problems.
Also I used swamp terrain as passable mountain terrain so you would have to change the campaign map textures for swamp.
Regarding the map's license, I've decided to make it public domain so everyone can use it without having to ask permission. You even don't have to mention me in the credits.