I'm from the land of snow & ice too (same part, actually, tamarack

well, originally; I've moved around a lot since I was little). But though I've seen people stomping their feet, I've never seen anyone quite so energetic about it. Especially after just waking up, really cold, in a tent! I know Ennis can move fast, but I know I would have moaned, closed my eyes and hoped I was having a bad dream, then slowly dragged myself out of the tent, cursing and groaning the whole time.

Hey, Jake - Why would Jack obviously have moved the truck? They were pretty busy drinking, and since both of them had just ridden/driven quite a ways (Ennis , anyway - looks like he started off in the night to get where he was going) I'm not sure they would have gone driving around town. Clearly somebody moved it, if it isn't even in the same parking lot (which I hadn't noticed), but why do you think it was obvious that they did? Just curious. 
In the story, they had to be trucked up to the trailhead; I just figured that Jack drove his truck to someplace where Aguirre said he could park it for the summer.
There's a screenplay draft in which Jack and Ennis sleep in Jack's truck the night before they head out with the sheep. (Except that apparently Ang Lee had to sit in for Jack, because Jake had other commitments for a short time in the middle of shooting. And Heath and Ang couldn't play the scene without laughing. Or something like that.) I'm glad that wasn't in the movie, and we don't see them sleeping close to one another before the first tent scene.