Ice persisted over labrador until about 4,500 year ago, right through the Holocene. We have good climate records for the past 10 thousand years. These records show us that despite the fact that the ice sheets had not fully retreated until about 4,500 years ago, the period between about 7 and 4 thousand years was a very warm period. It has been estimated that the temperatures of Europe and North America were about 2oC higher than present. At 4 thousand years ago the northern fjords of Greenland were completely free of ice and driftwood from Siberia reached the shores of Greenland.
Important difference exist however with the present.
At the height of the warm period Sea level rose rapidly between 7 and 5 thousand years ago as the remnant of the ice sheet finally melted.by four thousand years ago sea level was 3 meters higher than present day.