This isn't Byzantium relocating to the Americas or at least not immediately. Instead of Jean de Bethencourt setting himself up as the King of the Canary Islands, have someone who is of Byzantine descent yet closely aligned to Western European political sphere, maybe a scion of the Paleologos dynasty in Montferrat. Have him conquer the islands, populate the newly conquered Canaries with Cretans, Byzantine refugees and Calabrian Greeks. He sires an heir that doesn't become a tyrant like Maciot de Bethencourt, piss off the local Guanche and sell the islands to Castile or Portugal. When Constantinople falls to the Turks, the Paleologoi in the Canary Islands invite as many Byzantine nobles and soldiers to establish new lives in the kingdom. Cape Verde is similarly settled when it's discovered by Canarian-Greek explorers. Christopher Columbus goes to the neo-Byzantines in the Canaries and requests the king to fund his trip to the New World. The Byzantines accept...