I like to think of Ernest Shackleton's 1914-1917 expedition as the gold standard of survival exploits. While the climate may have forced it, it's noteworthy that all three men who reached the South Georgia whaling station were fully clothed (though they had not changed clothes in over a year!)

For all of human history and much of pre-history clothes of some sort were a high priority for most. There may be a reason for that...