So in this map, I painted which parts of the new continent the kelvash control. Now you can obviously tweak this to your liking but my idea was the clans learned how ships work by trading across that sea inside your kingdom.
Climate-wise, they can't expand below their current point because south of what you have is just frozen wasteland. The islands in the bottom right corner could be inhabited, possibly a starting spot if a new player decides to join, otherwise they're just uncharted.
Another thing, Rotafar is really the two original continents, but the inhabitants of the continents thought there was no other landmass and so they've called the whole world Rotafar. In reality, the kelvash can call the world something else, and you can have dialogues that refer to the continent of Rotafar and not the world
ex "A strange land we've sailed to, this Rotafar"
Finally, since the Feroci really only ruled over Rotafar, Orien has a completely different history and culture.
We should get to naming the other two continents, Orien and Dabs you can create some NPC kingdoms near you for extra realism.