I mostly agree, and that’s the point I was trying to make up above — that a trade network that reaches from Lake Superior to the Yucatan across the hostile territories without any overall governance makes crossing the Atlantic look tame by comparison. :’) The Vikings (and the English after them) entered the North American interior via Hudson’s Bay — during the medieval warming Scandinavians reached the Bering Strait by sailing east, because the route was open in the summers (private communication from a descendant of traders, for those who need citations). The Phoenicians (and others, for that matter) may have been chronologically well-placed to use the Arctic Ocean in that same way.
If Phoenicians were trading with Native Americans somewhere in North America for copper it would be really interesting to find out what they “paid.” It must have been cheaper or they wouldn’t go to the trouble. Probably impossible to find out, though.