Using Greenland’s grapes, the Vikings could have introduced “firewater” earlier and flourished; instead, the Vikings abandoned their settlements under Indigenous’ pressure.
The weather-not the natives-it got radically colder around 1000 AD-and the site in Greenland wasn’t a settlement in the sense of families farming, etc-it appears to be more of a port for ships to stop and get repairs done/get certain supplies, etc-no evidence of firewater or native interference-just frigid, windy climate...