The L’Anse aux Meadows site in Newfoundland is widely accepted in the archaeology community as a ca. 1000AD Viking settlement. The inglestad excavations in the 1960’s at L’Anse were well done, by all accounts.

Patrica Sutherland has been doing a lot of recent work on Thule sites (and potential Viking sites) dating to the late medieval period in the Baffin Island area. https://news.nationalgeographic.com/news/2012/10/121019-viking-outpost-second-new-canada-science-sutherland/

Small amounts of artifacts attributed to the Vikings have been recovered from contemporaneous Native American sites from the Maritime provinces up to Baffin Island. Schlederman (1980) provides an example of Viking chain mail from a Thule site on Ellesmere Island. http://pubs.aina.ucalgary.ca/arctic/Arctic33-3-454.pdf

I’d say the question now isn’t so much if there was pre-Colombian contact between Norse peoples and Native Americans, but how early the contact was and the extent and duration of the settlements.