I saw a documentary several years ago where a multidisciplinary team took a close look at the last Norse settlement. They concluded the evidence pointed to a sudden abandonment. They acknowledged several possibilities where the settlers could have gone, but their best guess was a ship picked up the last of them.
That is the best guess, imho, although I doubt that written accounts of that will ever emerge.
Y’know, I’d be surprised if there are no deep-ocean Viking wrecks waiting along the “Leif Erikson route” to America.
I had read about the abandonment of Greenland in Jared Diamond’s book Collapse. Here is a reaction to his analysis on the Greenland part of his book which disagrees with Diamond’s analysis.
http://www.barrelstrength.com/2013/01/12/jared-diamond-and-the-collapse-of-the-greenland-norse/