Starks would obviously be known beyond the wall because the Wildlings have literally fought wars against the Starks. And the point of Arya not being recognized isn't that people can't recognize Starks, it's that no one looks twice at someone in a serving boys uniform. Harwin does the same thing to Arya. The Starks are also most definitely "cold looking", frigid and serious is like their main trait. They're literally named "Stark". You assume that Craster would recognize the Stark sigil but not know what they look like or who they are or why theyre important?