Sounds like fun. :^)
Wow, trying to refresh my memory regarding the Varangian routes and portage spot(s) I got results about "The Varangian Way", an album by a Finnish group.
Anyway, [snip] The most essential routes included the Neva River, Lake Ladoga, the Volkhov River, Ilmen Lake, and the Lovat River. This set of rivers in the northeast can be easily connected to the Dnieper River, perhaps the most important river of Eastern Europe, which flows through modern-day Ukraine. And the Dnieper leads directly to the Black Sea. This allowed trade (especially slave trade) with the Byzantine Empire, hence the route's name – the "Route from the Varangians to the Greeks" [/snip] [link]
It wouldn't surprise me that the folks we know as the Vikings/Varangians lived in a lot of spots (because it's known to be true during post-Roman times), the Scandinavians' ancestors seem to have arrived in thee Germanic/Nordic migrations, and lived in the east, somewhere. The Indo-European language family tree is generally thought to be rooted in Central Asia, east of the Caspian.
One thing I read about it as a kid is, the words used for large bodies of water vary based on where the historical descendants wound up, suggesting that they didn't have a word for it and "grew up" in terrain that didn't have any.
Using Google Earth I also mile by mile followed the tributaries of the Volga north from the Caspian and they also nearly connect to the Reka which flows north to the White Sea. So that is another route nearly through by water.
So even if the “official narrative and assumption” that vikings didn’t know how to walk on land or use beasts and wheels, they could still hire locals to carry them on their backs the short distances between these waterways. lol
But I really do think prehistorically after the last ice age they originated from the Caspian area then migrated north as the Ice melted. I have often wondered if the early depictions of the Yggdrasil also served a second purpose as a map of these river tributaries that connected the south with the north.
If I ever get caught up and have some extra time I might play with investigating whether some of the earliest known Yggdrasil depictions will overlay and correspond with any of these tributary systems. Wouldn’t that be wild if they do? :)