Even IF you decide to take a trip to higher country ie over 6000' to 10,000 elevation....for a single trip, take what you got. You will be slower due to 30% loss of HP due to elevation....BUT, you will get there and back safely. especially when as noted previously, you have a 2500 chassis vs the same engine in a 1500 chassis.
My opinion due to 500K miles of towing various and sundry trailers from RV's to utility to equipment trailers, better to have a slightly underpowered rig, with correct gearing in the trans and axels, enough payload, than an overpower HP wise with under chassi'd rig.
Marty