Not much of a ship, that explains how they sailed to North America, reached Constantinople over rivers, portages, and the Black Sea, conquered Normandy and Sicily... :^)
While I agree with your list of Viking accomplishments, I would be willing to bet that the ships that were used in those endeavours were significantly larger than the one in this article.
At about 50 ft long and about 8 ft wide this was no cargo and people transport. It is a fast, short range troop transport or possibly a ferry of some sort. Depending on the availability of labor, construction time was probably a few weeks if that.