Up to the 14~1500's in NE Germany and around the eastern Baltic [Sweden/Finland] Not settlements had wooden Castles.
Stone castles arrived already in 12th/13th century.
If you see a picture of them, you see where Hollywood got it's forts for NW Territory Movies.
?Wonder how long it would take for the Iroquois & Huron Skalings to adopt Log Cabins and Forts.?
They already had them. The Mound Builder culture!
Now, assuming that there is a permanent settlement in Vinland - at least a few hundred settlers.
They have trade goods which the Mississippi Culture would learn to appreciate. Such as iron. Some iron was smelted in Iceland, and with abundant wood in Newfoundland the Vikings would promptly search and find iron ore.
The Viking ships would sail around shores of America and look for Skraelings to trade with.
Up the Saint Lawrence, Viking ships would easily sail to Montreal and Lachine rapids. Going on means portaging.
But the Varyags did not let the rapids of Volkhov stop them. They founded a town at Ladoga, and went on to Dnieper and Volga.
Now, how far south could they go along the Atlantic shore?
In 850-s, the southernmost permanent and safe Viking settlements were in Ireland. Danelaw IIRC was founded a bit later. The Vikings made short winterings at the mouth of Loire, but did not stay permanently.
Now, a Viking fleet did, in 859, sail all the way through Gibraltar and into Mediterranean Sea. Raided for several years into Italy etc. But they met discouragingly strong resistance (most were lost and some returned to report).
The Vikings in Iceland and Greenland did spend some time exploring. Many settlers of Iceland circumnavigated the isle. Ingolfr Arnarson spent 2 years exploring the southwest coast of Iceland. Erik the Red explored Greenland to the far north during his 3 years of outlawry, before settling in Eastern Settlement, so when the settlers came, he pointed them to Western Settlement and hunting grounds far north.
Could a fleet of Vinland Vikings explore to Gulf of Mexico?