I'm thinking a Fuegian group (maybe the Yaghan) settles the Falklands from Tierra Del Fuego, South Georgia from the Falklands, the South Sandwich Islands from South Georgia, the South Orkneys from the South Sandwiches, the South Shetlands from the South Orkneys and mainland Antarctica from the South Shetlands.
Could they survive in these places? What would need to happen for them to island hop? How would Europeans react to finding people in these places? What would their lifestyle be like?