I completely understand the weight issue that you guys have mentioned.
My wife and I are both experienced backpackers, and spend much of our free time in the wilderness, be it hiking, climbing, or paddling (we actually met each other in a mountaineering club years ago).
We've more or less done it all... Summer ultralight backpacking to full-on winter mountaineering. If I've learned one thing over the years it is that I hate heavy packs on days with a lot of vertical!
So, weight is a factor...
But, by the same token, having a cartridge that is up-to-task is also a factor. I don't suspect that the two legged predators will be much of a risk where we want to go up North, and I really doubt my .45 would be worth a damn against the big bears that roam those parts of the country.
Thus, I'm trying to find a compromise: Something that will work against the only targets I might have the occasion to engage with (large land mammals), but isn't too heavy to carry (again, a relative term).
I've also considered a large revolver as an alternative to a long gun, due to weight factors (perhaps .454 Casull?). But, the rifle obviously has more punch!