It's a known fact that, by the end of the XIV century, Greenland's Norse colonies were suffering economically and socially as a result of worsening weather, shift of trade routes, possible conflict with the Inuit and other issues. By 1380 the Western Settlement had already been abandoned, but in 1408 - when the last known account about Norse Greenland was written - the Eastern Settlement seemed to be alive and relatively well.
Then the Norse just seem to vanish from Greenland.
I've read some sources here and there claiming that some archaeological findings, such as the ones at Herjolfsnes, lead to believe that the Vikings inhabited in Greenland at least until around the mid-XV century - which wouldn't answer my question, it would only shift the time limit. There are also other sources, like Seaver's The Frozen Echo, which seem to have much more information about Greenland in the 1400s than what is available to the public. I've even read a story about an Icelandic sailor known as Jon the Greenlander that was blown off-course to Greenland around 1540 and happened to find the dead body of a Viking in a house near the beach.
I'd like to know how much of this is true. Is it possible that the Vikings just died of cold and hunger in complete isolation? Has the archaeological research progressed any further in the last years?
There's a Denmark-based international research group that's been pushing hard at this question in the last 5-10 years (although the project goes back to 1982 or something nuts like that); Journal of the North Atlantic has had a few special issues devoted to archaeological and paleobotanical research from various angles.
Earlier presumptions of a high medieval shift to a marine-based (hunting/fishing) diet instead of livestock have been confirmed, along with some evidence of attempts at cereal agriculture that were similarly abandoned in the 13th-14th century (Ledger et al. 2014). So the Greenlanders were adapting to whatever the changing conditions (environmental, trade) were throwing at them--while it was still useful for them to hold on.
Traditional and bioarchaeological work has shown a couple things that point to Greenland being just "not worth it" for 15th century residents. First, we've known for awhile (Berglund 1986) that basically no valuable items (personal seals, rings, weapons) were left behind. Scholars now see this as evidence of purposeful abandonment and taking their valuables with them.
Second, Lynnerup 2014 argues for gradual decline rather than sudden collapse. That is, that over the course of the 14C in particular, environmental and economic conditions made Greenland less attractive to new immigrants (there are fewer and fewer female skeletons found) and made emigration more attractive (new and improved opportunities in Iceland; changing trade patterns and economic conditions after the Black Death and new trade routes).