I'd say change the oil and put in 15w-40 to drive down, and keep the rpms low and engine load low. Denver to CO springs isn't too bad of a drive if I remember correctly. It may make it.
Or put 20w-50 in it and trade it.........I'm not really serious, but it could be an option. I had an acquaintance 20 years ago that put 80w-90 in an old camaro to mask the rod knock when he got rid of it. I could never do that to a person........maybe a shady dealership though.
I did trade in a 2009 Denali because all of a sudden it started drinking oil on a road trip. It was a beautiful black XL. But, I was tired of the piston slap that never went away and dropped it like a bad habit for a pristine 2017 Denali. I don't feal bad because the salesman said it would go to auction because it had 165k. Somebody got a nice truck for pennies I'm sure and put a motor in it.