Erik the Red named the icy, cold land he discovered "Greenland" to con other Scandinavians into following him there. It was barely habitable then, and when it cooled off into the LIA, it got appreciably worse.
Reread the Sagas and the recent reports of teh scientific excavations. The Vikings did pasture cattle on Greenland. There were no vines growing there, and that was both Hugh and series to them.
All reports are congruent on the Viking love of mead, wine, etc.
Vinland, probably Newfoundland or perhaps part of New England, well may have had vines during that warm period.