HI, and first good luck . You will be climbing all the way, and with a 1500 . even you have a 6.0 and the 3.73 gears , I have 2500 and have come across that are several times with slightly less weight.
Count on more fuel usage and I hope you have an extra cooler for the tranny if it an automatic. Your 1500 may not have the cooling system for the climb. If it does start to get hot just pull over and take it easy.
I do not want to dissuade you from a great trip though. Keep your speed down and watch the temps.
The roads are not all that bad except the short tie in OK about 45 miles to Colo. Then it is a pretty good trip. If you can stop at the Sand Creek Historic Site if you are into that kind of stuff.
Stay safe and have a great trip.
Chuck