The key here is the relationship of speed to G loading if evasive action is needed.
The product of moving a fixed amount is squared with increase in speed.
Of importance is the .3 G limit for almost guaranteed safety. If the combination understeers at .3 G then the trailer and tow vehicle will be safe.
Faster means the G loading will be higher.
Personally not towing I drive about 72 mph and if being overtakenI just stay in the right lane.
If I am going faster than the traffic I am obviously catching, then I will pass as soon as it is safe. If I were not faster I would not have caught up with them.
I notice that 72 will result in your constantly being passed. The problem I have is that at 72 mph I will catch up with cars being passed by another car at a speed differential of about .003 mph. Trucks passing other trucks also are a problem.
I hate to dawdle next to a large truck or RV. If you have seen the result of a tire blowing out you will understand.
The trick is to plan ahead and make allowances earlier rather than later.
I will try to slow before getting to a stopped (red) light
so that I don't lose very much speed after the light