I think that some may be really hung up on the 65mph number and what that means. Yes, I agree that exceeding that speed isn't exactly a good idea.
But these statements alluding to towing @ 65 isn't a good idea because it is so close to the max speed rating is just hogwash.
Everything sold in this country (for highway use) has a "safety factor". In other words, 65pmh is the max RATED speed. In even other words, the tires can spin faster. In fact they were designed to spin faster.
So, run it at 65 mph if that is safe for your situation. Limiting your speed because you feel that 100% of your speed rating is more unsafe than running at 90% is undermining the entire idea of a rating system in the first place. Of course wear an tear will be greater with any tire with higher speeds. But that doesn't exactly translate to being any less safe than rolling slower.
Some just over think too much