Earlier acquisition of ploughs and sails would mean the Vikings hit the seas at the same time as the Saxons, Angles and Jutes. The Irish and the Franks were also more resurgent then.
They would raid and settle in many of the same places, but they would face stiffer competition and very likely get repelled. Other factors as on OTL would then kick in and the Viking age would come to an end a la OTL. The Viking regarded as just another Dark barbarian horde.
On Greenland, it being colder, it would not be settled. Iceland and the Faroes would be settled. In their case, it was just a matter of a decent ship and a lucky discovery. Withe right vessel the Picts or other natives of Caledonia could have got there first.