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Norse culture developed largely in the area centered around the straight between the North Sea and the Baltic, particularly in what is now northern Denmark and southern Norway and Sweden, at roughly 60 degrees north latitude. This was a largely maritime culture in communications and trade that relied on agriculture specialized for living at this latitude for sustenance.
During the Viking Era, Norse people raided by sea wherever they could of course, but when they looked to colonize, it was in areas near the sea (or in the East really good rivers), where their agricultural package worked best. This ended up being in boat-reachable areas between about 50 and 70 degrees north. They colonized all of these places that they could get a good foothold in (including for a while, northern England).
A person can perhaps be forgiven for not seeing this immediately, because standard maps used in historical sources often use projections that are meant for more sunny climes, but greatly distort distances or latitudes in the far north1. I've attached one below that preserves distances, so it isn't too bad, but you still have to realize that latitudes curl up towards the corners a fair bit as you get near the left and right sides of the map. To give you an idea, Normandy is about at the same latitude as Newfoundland (Vinland)2. That southern Greenland colony was at about the same latitude as Oslo.
So what you should be able to see from this map is that the Norse settlement pattern makes pretty good sense from their perspective, and nowhere are the open-ocean distances they had to sail from one to the next closest any worse than the distance from say Denmark to England (which is exactly what the Great Heathen Army did).
In fact, thinking about it in terms of sailing distances should be more helpful, as well as noting the late dates for the colonies in the Western Hemisphere. Norse Greenland and Vinland are perhaps better thought of as Icelandic colonies, rather than purely "Norse".
1 - Close to the poles, the rule for projections is: "Distances or latitudes: pick one"
2 - One can argue in this case that isn't too bad, because prevailing currents in the North Atlantic make the climate there much colder relative to Europe, and this curling projection can be seen as a good hack to help depict that. Latitude matters for crops too though.