The tent and sleeping bag you mention are suitable for high-altitude mountaineering. That is, pretty extreme conditions. From what I've read, it gets pretty cold in Korea, but the people who've been there before are probably your best source of information on what kind of temperatures to expect, etc., assuming they've been there at that time of year.

The Gregory Baltoro 75 is a very good pack, and while five pounds is heavier than many of the newer packs, it's not excessive for winter camping with a more-or-less traditional approach (i.e., not ultralight). You need more and heavier stuff in the winter, generally.

You don't mention your age or level of fitness, but 43 pounds doesn't seem excessive for a winter trip, again assuming a traditional approach. I'm smaller than you by quite a bit, and I've carried that much without too much trouble in my younger years, and I'm not particularly strong or athletic.

I notice you included 3L of water. You may not have to carry that much, depending where and when you go.

Since your Korea trip isn't for another year, I imagine you'll wind up with a different set of gear for near-home adventures.