It was never 'ice free' in historical times, but during the Medieval Warm Period it was settled and farmed around fertile edges. If we get some more melting on this cycle, archaeologists will have a field day rediscovering Norse settlements.
Unlikely, at least not for this reason, since the coastal fringe always thaws every summer anyway, and possible early settlement sites have thus always been available for excavation. The two main settlements have already been well studied by the Danes.