People back in mainland Europe definitely heard about Vinland and fairly soon after the Norse showed up there. The earliest written account of the discovery of Vinland is actually from a German source, The Deeds of the Bishops of Hamburg written by Adam of Bremen and published in 1075 - two centuries before the Vinland Sagas were written down. While visiting the Danish court Adam heard about the discovery of Vinland. He doesn't have much to say about it about it though. He only lists it among other northern islands like Iceland, Greenland, Helluland (probably Baffin Island), and Markland (probably Labrador).