I tried going barefoot and loinclothed in the snow way back in my younger days and nearly made it home
a few years back on a day in January with temps in the 50's, but snow and ice on the trails, I tried it and could not continue after a short period of time
but he is a lot younger and in better physical shape, so I'm sure that makes a huge difference in endurance
I also watched his videos and they were all great. He wore a traditional Japanese loincloth called Ettyu Fundoshi. I have one of my own too. But I never have the chance to wear my loincloths outdoors.