One of the major problems the actual Greenlanders had was not having enough ships of any quality.
Not sure this is a problem. Greenlanders were sailing to N.A. for nearly 500 years to trade/resource/explore. Evidently they were keeping enough ships built (imported lumber from Markland/Vinland) to supply their own needs. Newfoundland and the surrounding areas have bog iron. Therefore everything you need to build ships (wool for sails from sheep).
a colony at Halifax will site them close to cod and halibut on the Grand Banks and whales in the Gulf of St. Lawrence.
Ironically the fabled Vinland settlement of Hop was probably in the Gulf of St. Lawrence. Two reasons for this. During the winter there a whale washes up on the beach (they butcher it for food) - a whale none of the icelanders recognize. The only whale in the N.E. Atlantic the Icelanders would likely not recognize is the beluga whale (their range is not around iceland)...and there is an isolated pop. of belugas in the gulf of St. Lawrence.
That coupled with the fact that the Gulf has wild grapes along it's southern shores and butternuts (the nuts which were found on the waystation on the northern tip of Newfoundland), point to the fact that "Hop" (the vinland settlement) was in the gulf somewhere.
Anybody know what the indians that far north grew/farmed at this time?
They were hunter/gatherers at this time - i believe the three-sisters farming package was just reaching into what would OTL be modern canada during this era.
The important thing to remember is that the Vikings are master mariners,
This ^ x 100.
We know that OTL the Norsemen explored the east coast down through at least the Gulf if not further south, Hudson and James bay (and up those rivers a ways), and a good portion of the Canadian arctic (maybe even the entire northwest passage, for they reached Victoria island). They even reached Ellesmere and Axel-Heidelberg island (furthest north of the arctic islands). Some research suggests they even established a trading fort/summer camp (i've even heard it suggested that it was a permenant settlement, but have yet to see evidence for this) on Ellesmere island :O
If the settlement of Hop is successful and soon grows to any size, expect even more thorough explorations of the northeastern American continent and within a few generations they'll have likely scouted all the important areas east of the rockies that can be reached on rivers/lakes.
Cheers
Edit - as you can probably guess the Norsemen in America is a hobby of mine. I've reach and studied a good deal on this topic and if you have any questions please feel free to ask me.
