Let me see if I can get this wreck back on track.
Yes, I would really survive. Not necessarily based on my body weight, but my knowledge, skills, and gear that I depend on. I'm a long time believer, after years of excercise, eating right, and being active, the body will grow to the mold.
Which means, my body adapts to its lifestyle, its a difficult time, when you're bodies adjusting, but survival is based on a myriad of variables, some you can control, others not so much.
Could I win a 5K race tomorrow? No, I would die. Pure and simple. Could I get my fat, saggy, smoking carcass across the 5K mark, yes, yes I could. The difference is time. I'm not built to be a runner, never have been, even when I was. I'm built to be a tank. Slow, heavy, and knocking down everything in its path.
I do believe that in a "survival" situation, a slower metabolism is a greater asset, than a higher one. I won't need to eat as much, and I carry around fat reserves that will keep me working without food, longer than a bean pole with a hypermetabolism. I've seen it in action. I've seen very large, muscular guys, very fit, and in great shape, lose damn near all mental faculties, after just a single day without food. He was used to eating 5-6 times a day, small light meals, etc. When he needed food, and didn't have it, he lost his edge, a clear head.
Me, I can go a few days without eating, no problem. I do it at least twice a month, to make sure I got the mental side of it down, quell the big hunger pains, drink water, and stay focused on being active.
Food is not even in the 3 most important things in a tough spot, or "survival situation", its really not in the top 5 if you wanna get real technical about. Fitness on the other hand is good to have, but endurance is almost paramount. Just because I can't work as fast as you, doesn't mean I won't get my work done. Its about conserving calories, and energy, not about bushcrafting a nice living room.
Moose