I think you're over thinking it a bit, and sort of selling yourself a problem.
Unlike most games with a "fog of war", where the assumption is your character either has never traveled outside of their village in their lives, or has never had enough contact with the outside world to know what their surroundings look like, CoE assumes that your character is learned.
While they may not know every detail of the continent, it's understood that your characters are smart enough to know there's an ocean or lake a couple hours north of where they are. Just as I know if I go west of Seattle I'll hit water.
The benefit of being an explorer comes not from the high-level understanding of what the continent looks like, or even where the biome boundaries are, but in the low-level details.
Where do animals gather & breed, where are the natural resources located? Where are good places to gather minerals? Where are there ancient ruins, graveyards, catacombs, etc.
It's also important to note that Elyria is not static like other games. Elyrians relocate, abandoning old settlements and creating new ones. Animals migrate in order to find greener pastures or to escape harsh winters. Resources deplete and new ones need to be discovered. Even forests recede from deforestation.
The point I'm making is that even if we were to provide a fully defined map for you, with every single domain, lair, catacomb, dungeons, river, forest, hill, etc. mapped out based on the world as it exists "today." Tomorrow it would be different and require re-exploration.
As a simple comparison, look at this map of North America, and compare it with what you may already know about the countries located here. Clearly there's a ton you'd learn by exploring vs. just looking at this continent map.