Within the last 10 years genealogists have started using the DNA samples of people now living to piece together information about common ancestors.
Proof that the survivors went native may be discovered as DNA research continues.
I wait for that, and for another similar "mystery" about the disappearance of the Greenland colonists when the Medieval Warm slid into the Little Ice Age. I suspect they gradually increased their hunting and went for longer and longer hunting trips as agriculture became less productive. They had met and knew of the indigenous folks and it would be natural to accompanythem on occasional then more than occasional walrus and seal hunting trips. I would bet that the Inuit have traces of Nordic genes.