In general you shouldn't have to worry about engine oil temp towing anything near or at the truck's tow rating.
250 sounds high though for cool weather, but idk what you were doing with the truck. Watching the gauge after a full throttle pull up a grade, or cruise at 60mph on a flat road?
Either way, Dino oil is good to at least 260 ish without any ill effects. Syn is good north of 300deg.
Were your trans and coolant temps high as well? If not then maybe you have an issue with oil cooling.
If it makes you feel better, I'm not a newbie to towing and can't say I've ever looked at oil temp (well, couple times on my new company truck that has the feature) and have never blown an engine.
Change the oil, keep an eye on it and see if it was relative to the conditions or an anomalie.