Well, for answering this question I think we should make a division between "viking culture" and being actually a viking.
The vikings, as everybody know, were so-called because they did raids. These raids, or at least the big ones, stopped after their defeat in Stamford Bridge. If there was another raid after this date, probably the people "raided" would have talked about their barbarism, and we would have a new source that would change the history as we know it.
Of course, vikings lived after the battle of Stamford Bridge, and some of them could possibly worship the ancient gods (realize that Snorri Sturluson, who wrote the Eddas, lived in XII and XIII century, so the tradition had to continue), and live the same way, with the same laws (one example could be the Icelandic Althing, that hasn't changed since then)... but they didn't more big raids, probably because the Normans (direct descendants from them) came to an agreement, and they didn't need to do another dangerous raid, and the little villages of the north could possibly do raids, but not so big and between themselves.
At least, that's what I think