Another one to add to your RTW options. Starting December LAN will commence flying SCL-USH (with stops in Puerto Montt and Punta Arenas).
Ushuaia on the southern coast of Tierra del Fuego is a beautiful little frontier town or at least was 14 years ago when I went there. Lots of National Park and wilderness areas to explore and some of the most magnificent scenery you'll ever see.
Probably more a late spring/summer/autumn destination - but it does have ski lifts behind the town on a thing that they rather extravagently call a mountain (similar to Winnipeg's Riding Mountain)

At 1486 miles SCL-USH is just a little short of a flight from Chile to Brazil and for those Flyertalkers who are a bit reluctant for safety reasons of spending time in the other South American cities that LAN serves (eg BOG,CCS,GRU,GIG) USH gives another Mileage run option that will without a doubt be worry-free (except for those assassin penguins)

When I was there they were proud of the new international airport they were building to accomodate the 747 that AR flew EZE-AKL which had to make a refuelling stop in Rio Gallegos on the outbound leg. The longer range of new jets meant Ushuaia International Airport never saw those planes - now it gets to fulfill its destiny