Yes, MisterK is correct that Sten was actually one of the Zori Cloudlord leaders, not one of the Myri; I misremembered that. He is also right that the Myri culture doesn't quite fit a Viking-Age Norse culture.
On the other hand, the Myri do look very much like the Norse (and indeed another name for the Myri in Shadow World is 'Northmen'). They have blond hair and blue eyes, are tall and fair, and are said to come from the northern climes. MisterK prompted me to go back and read a bit of the Haestra region in the Master Atlas for Emer, and you can see some Germanic influence in the names of the Myri towns in NW Emer (Haestra), as for example in towns like Carlsdale. Gravesdale, Milldale, and Yorndale are all coastal towns in the NW of the region of Bodlea, in Haestra (NW Emer) in the Emer I book. The wind from the sea is said to be cold and rainy. So I think that might be the best setting for the adventure if you wanted to find the best Norse equivalent: it's not Viking-Age Norse, but you could pretty easily fit it into pre-Viking Age Norse, and the people would look very Nordic at least.