Assassin's Creed fansite Access the Animus has worked with Montreal's Kanien'kehá:ka Onkwawén:na Raotitióhkwa Language and Cultural Center to translate all of the unsubtitled dialogue in Valhalla's Vinland arc.
The video below reveals what is being said in all of the conversations going on around Eivor in this part of the game, which she (and you) are deliberately left unable to understand.
As well as dialogue, it includes translations of item descriptions and more. There's also a fascinating explanation of the Mohawk creation myth Eivor hears around the campfire - previously told by the Oneida tribe in Assassin's Creed Rogue. Intriguingly, there are differences in the stories which accurately depict the differences in its telling by the two tribes.