Overdrive?

I would put it in tow-haul and let it do whatever it's computers says it can. Within limits. For example, if it kept shifting gears all of the time, I would downshift till it would mainly stay in the 1 gear.

Sounds like you have an automatic and newer TV, so double OD with a tow/haul button

Automatics and the tow/haul button designed for folks who do NOT want to manage
their own selection in gears...so follow your glove box manual on HOW2 use
the automatic and tow/haul button

I say, leave it in OD, initiate the tow/haul button when hauling and/or towing

Leave cruise off

Use Tow Haul period.

4th or 5th if your rpm's are high slow down. if your using more than half throttle shift down...

Would depend on how your TV is acting. Will it hold OD while towing, or does it shift alot? Is the engine running free, or is it lugging / struggling? IF it's running free tow in OD. IF it's lugging, down shift untill it's runnig free. Lugging will use more fuel, and can cause the engine to begin to use oil.
You should be able to tell what gear the engine likes to tow in. Mine don't like OD. It luggs. It runs free in what is 3rd on my TV. While running in third the engine is way happier, running in it's powerband, burning all the fuel going to it, and I have much better throttle response, plus it does not gear down as much / so far on hills. Plus it actully gets better mpg, as the engine is not working so hard to hold a higher gear.
Just because you are in OD, does not mean you are getting better MPG, Or that it is not working harder.

Your results may vari.

These threads are a general discussion on the subject, not specific to your situation.

Towing in od
od 2

So are you saying to put it in 4th and leave it there? I am a bit dense and am looking for a more precise answer.

I can provide a ton of posts about towing in OD.