I have a number of big knives in my collection, but in practice I rarely schlep them around in the great outdoors. I guess I find them too cumbersome for fine work, and too small for heavy work.

As suggested earlier, the practicalities of local terrain and vegetation dictate the most suitable tool. The machete for jungles is a good example, proven over time.

Historically, the most suitable all-around "big knife" for northern forests has proven to be a short axe (24" handle).

In my portable kits, the "big knife" of choice has ended up being a Cold Steel shovel paired with a saw.