On the latest stream I noticed that Scandinavia and a few other places have the map cut off right on top of their lands. My suggestion is to add on a little bit of uncolonized space on each of these peripheries and edges of the map so those regions always have a little bit of space they can grow into without having to conquer their neighbors. Certainly in regions where that land would be perfectly habitable, but just happens to be on the arbitrary edge of the map.