May be a difficult one to answer but here goes, My 2012 350 diesel just turned 80,000 km. Out of this I think about 40k was towing a 8k fiver for three years and this year a 15 k toyhauler. Thinking ...
On my 2011 I did front brake pads at 113,000 miles and rears at 114,733. I could have easily gone longer on both but they had an annoying squeak (not the wear indicator) that I was chasing so I replaced them. I would just pop a wheel off and see what the pads look like. You might be surprised with how long they will last.