Viking tents are known from boat graves in Norway, i.e. the Oseberg find from 834 AD and the find of the Gokstads-ship from 900 AD. The tents have likely been part of the ship equipment. The ship was "camped" by putting up the tent within the ship, but it could also be used on land.
Written sources also mention using tents on land, but there are currently no examples of this in the archaeological material. Maybe the partially sewn together birch bark flatbeds from the Valsgärde-graves in Sweden from 750 AD can count as tent remains or remains of tarpaulins.
The problem with only knowing of Viking tents from the two ship graves it that it paints a very stereotypical picture of what tents looked like in the Viking age. Wherever you go only these tent models will be "approved". Obviously there must have been a variety of other types of tents. Until the archaeologists uncover remains of other models we will have to make do with the limited material.