You might be surprised at what you have would work.
The gearing looks just right to go over mountain passes with a load.
Your big feet with a rack and panniers? You will have to answer that yourself.
If the suspension locks out that is a plus. Otherwise, maybe just replace the fork.
On a long tour your hands might need more positions so a modification with a new trekking bar might help or just some bar-ends.
I went from Mexico to Canada on something like this bike (15 years ago). I only have size 9 feet, though.