Although the BK2 is a beast and is an awesome knife if you are going to have just one, I think that there are a lot of other considerations to make based on the length of these excursions. I would not want to chop and split wood with a BK2 for 5 plus days at a time. That's some serious calorie burning and as awesome as the knife is, a two tool set would be more efficient for you if the extra weight isn't an issue.
I'm in the woods 6 days a week at the moment and I carry a BK5, large Victorinox, and a Cold Steel Pipe Hawk with me every day. The Pipe hawk is great at cross-cutting, I can baton decently with the BK5, and the Victorinox is great for a variety of other tasks. I would suggest this kind of approach. You'll spend many times the calories processing all of your wood with just a BK2. In my opinion, the Tomahawk is a more versatile tool than a Kukri so maybe it's something you'll want to consider.