A cooler for the trans will be very helpful. Keep you speeds down to minimum and not actual highway speeds. Give plenty of braking space.
I towed my 16' Scamp camper to Zukimelt last year in July in MO to IN. 3+ hours into the drive, my 'Check Engine' light came on. The camper weighs 2100# empty, had couple bikes, coolers, little food, etc. So I'll assume 2500# and that's pushing the guess. Anyways, the trans will get hot and real hot. Engine didn't have a problem. I didn't keep OD out and the trans kept having to shift from OD to 3rd on slight inclines, then on hills, down to 2nd. Once I arrived at the camp, I let it cool down. Next day, light was off. Same thing happened on the way home. Once home, I changed the trans fluid. Still haven't added a cooler, but will get to that before I tow with it again.