Absolutely they did. They also didn't wear clothes, or have shelters with walls. So if we went back to that, we could definitely stretch out a few more decades

Absolutely they did. They also didn't wear clothes, or have shelters with walls. So if we went back to that, we could definitely stretch out a few more decades of habitability. It's also fair to say that the temps, even as few as 500 years ago, were much different than they are now.