Okay, so first off, víking is a job, not an ethnicity. It would be like calling all Americans cowboys.

Secondly, while Eíriks saga rauði and Grœnlendinga saga were written ca. 1220-1275, the issue is that Iceland and Icelanders were (and still are) an incredibly small populace. There was little enough contact with North America, and no colony like in Greenland, to make it an attractive point for settlement and, frankly, there wasn't the technology to bring sufficient resources back to Europe to make it profitable or reasonable to trade there.