Having a successfully-settled Norse colony in North America is one thing, but that notion alone won't mean that none of the European kingdoms won't conquer it.
One of the peninsulas in Newfoundland would liekly be the first site of the settlement. The indigenous pre-Boethuk population on the island number no more than a few thousand and live a hunter-gatherer lifestyle, so contact with them may not be so frequent. If warfare could be avoided until there are several hundred Norse settled in the area, it could be secure enough to effectively displace the "skraelingr" in that one region of the island before clearing forests to build farmsteads.
If the Norse Vinlanders become Catholics early on and maintain contact with Europe via Iceland, that might give some pause in any plans to conquer a Christian state, although, if it was excommunicated for some reason, or if an ATL Protestant movement takes place, it could come to pass that countries like England may view Vinland as a potential colony, assuming it still has a relatively low population density. Although, if it becomes Christian early on before the age of colonialism, it would be well-enough known for people from northern Europe to travel to and settle. The Hanseatic League may direct some of their trading ships there.
If the first Vinlanders remain Pagan, then the region could become a valuable source of materials with Iceland, in terms of timber and furs. And if, for whatever reason, Iceland remains itself Pagan, then some Pagans from Scandinavia, under increased pressure by their rulers to convert, may leave Denmark, Sweden and Norway and end up in Iceland as a likely haven. After a while, becomes apparent to the new Pagan refugees of Iceland's limited landownership among the Gothar-class, so some may learn about Vinland and make the decision whether or not to go there. If commercial contact is maintained with Europe, they just be able to access some of the technological breakthroughs going on in Europe, though they may only get things like gunpowders possibly decades after everyone else.
But to have a reasonable level of commerce with Europe, they need some exotic things which Europe may need or simply desire. Iceland really needs little more than just furs and building materials, and would become dependent on Vinland for those. If the Vinland Norse sail through the St Lawrence River, they may get to meet Native Americans with squash, corn and tobacco. With these, than direst trade with the authorities in Europe would be likely.
There's no guarantee of an ATL Vinland become a formidable regional power to challenge European intervention by the 1400-1500's, but these may get it off to a respectable footing when the time comes.