There are snow fields in his video, he camped rather low that one night in a valley that looked pretty darn green, and it seems this was very early in the season. He also moves mega miles a day, so he probably did ok carrying a gallon or so.
I've seen some of his other videos going off trail in the Sierra just on a whim, not knowing where he was heading. Rather sketchy at times, and he clearly lacks the kind of "what if" concern that keeps people like me from trying things I haven't researched to the t.
That is a really cool video. #1, it is fun to see the guys resurrect such an old relic. But #2, the video photography is outstanding -- someone put a lot of time into creating the video, even with drone shots.
It is pretty amazing, those guys with the skills to get an old van working. Funny parts: the mold left on the front windows, but the gleaming sticker fixed to the back one. And using a little one-hand hatchet to get that fallen tree out of the way.
the video tells a great story, and from a perspective that lets you almost participate. A little adventure found in the modern world, sprinkled with a little nostalgia, nature, and campfire camaraderie. Well edited and produced and a lot of fun to watch.