As far as taking a lot of junk with you, IMO better to have it and not need it, than to need it and not have it. I just keep my pack below 40-45 lbs.
I was on a guided hunt in the Czech Republic. The guide dropped us off at 2:30-3 Oclock ànd pointed us in three different directions with a wave of his hand saying there was a shooting tower out that away. Overcast, dark as heck I wondered off through fields of Rape in the direction indicated. I got pretty wet from the dew and eventually found the shooting tower. I'm used to cold weather, seriously cold weather, but this time the perfect storm hit. High wind, a degree or two above freezing. sideways sleet. I put on every piece of clothing I had with me and put my feet in my backpack. Long story short I got hypothermic. Finally decided it was either move or die and wandered off in a likely direction, I eventually saw a light about a mile away. I almost fell in the door of a farmers house. They got some hot soup in me but I eventually passed out anyway, I was out of it for hours.
Anybody who says it can't happen to them is delusional. I've logged forests at 10-15 F for ten hours and never had any real issues with it, but just the right circumstances can be a killer. After that trip, I always carried a big block of Chocolate, a tin of Salmon and a thermos of sweet Coffee when possible, even on short trips, for a metabolism boost. My biggest mistake was I hadn't eaten right for a couple of days prior to the hunt. The least painful way to learn a lesson is from somebody else's screw-ups.

I always open up my game as quickly as possible and prop it open with a stick, the quicker it cools the longer it lasts.