People keep migrating, to this very day.
Some groups travel very far as a group, or in in a wave of groups. The Finns, whom you mentioned, have a very distinct language from other Scandanavians - a whole different language group. Finnish langauge is of the Uralic group, mostly distributed in modern-day Russian (but also Hungarians and Estonians).
Central Asian people repeatedly covered long distances in large groups in relative modern times. After the fall of the Hunnic period in what is now Mongolia, Huns traveled to gates of Rome, where the Pope came out to negotiate with Attila, and married a Roman princess to him. They founded Hungaria. The Bulgars from northern Central Asia migrated to found Bulgaria. It was possible even in ancient times to travel great distances by land in a single generation
Three big waves of migratory peoples came from Asia to America over about 15,ooo years to populate the Americas, before the major European migration after Columbus.
It is entirely possible that a large group developed ocean-going technology during the Stone Age (like the Polynesians did later, but with Stone Age technology), aand lost the technology in a few generations after migrating a great distance.
The Hungarians call themselves Magyar and say that their ancestors descended from Noah through his son Japheth. Their language is in the same family as Estonia, Finnish, and Samoyed. There are Magyar today living along the Nile. It has yet to be determined whether the Nile is the point of origin of the Hungarians’ ancestors, or whether the Nilotic Magyar-ab represent back flow. Still lots we don’t know.