Many years ago I did quite a bit of pipe fitting in a chemical plant. We did manage on 2 occasions to break a 48 inch Ridgid aluminum pipe wrench but never a steel wrench. In fairness, we had 3 guys pulling on the wrench with a 12 foot cheater bar when it broke. Most of the time the same 3 guys and
12 foot cheater just got the job done without incident, regardless of whether we were using a steel or aluminum wrench.
FWIW, I doubt a single person could break a 36 inch aluminum wrench by himself without resorting to extreme measures. Also FWIW, for home owner use, I've never had to use a pipe wrench larger than a 24". (Though there were a few times I wished I had a bigger one!)