There is a recommended max size for maps since you will run into replication issues otherwise. Not sure how big it was but the original island is quite close to that. A Wildcard member mentioned it once but I cant remember. Might be worth doing some research and testing before commiting to such a task.
A here is some additional feedback from my side: It might be worth, if you try something smaller first and get an understanding of the tools. Correct me if I am wrongm but judging by the fact that this is your first post in the UE forum you haven’t done much mapping for Ark already, right?