You do realise that there is a price to be paid for all this advice, when you get back you’ll have to show us all some photos!
As for your original IQ test I think you just took two cars put them both into first gear and drove them both down a straight road. Ok maybe not the best analogy I’ll probably get burned for that
I don’t have either of these camera’s but I do know which one I’d rather have on a trip like that, 5D3 hands down
1. Weather sealing
2. High iso performance for real fast shutter speeds (doesn’t sound like you’ll be taking a tri-pod) mono-pod?
3. AF for animal action
4. FPS as above
When you are using the above that’s when the 5D3’s IQ shows
You might also want to have a quick read of thishttp://www.canonrumors.com/reviews/ef-70-300-f4-5-6l-is-review/
PS Shoot RAW