I tow a small Trailer w/my SUV, so I don't have a Dog in this fight, so to speak.
'jimcumminsw' gives some good, and widely seen, advice: get those 3 Gauges installed. Many of the guys I see around CO High Country have those 3 Gauges on the A Pillar [Driver's side] for easy monitoring. The thinner air up here really affects the 'thermals' of cooling, especially when pushing Vehicle limits. I see Trucks and 5ers/Trailers pulled over every trip transiting I-70. Knowledge is power, in terms of Gauges.
Besides the >20% less air up here to carry heat away, an unexpected kiss-of-death for you is when a Truck hauling Drilling Pipe loses a load, or there's a crash. Folks, including me, wind up in stop-and-go Traffic on the approach to the ~11,000'-high Eisenhower Tunnel or ~10,500' Vail Pass. My Electric Cooling Fan and oversized Tranny Pan can do only so much. I have to shut off the A/C and watch my Auto Tranny gear selection as my Engine Temp climbs every such Towing incident. This same stop-and-go heating occurs in Mountain Towns as you take a 2 lane Road to a scenic destination, or exit for Fuel or a Meal. On the flip side, there's not a trip yet where I don't see smell/see burning Brakes on Big Rigs - even empty ones - going down the Georgetown and Floyd Hill 6% Grades into Denver. I gear down and take my sweet time.
While it's not exactly what you plan to do, you might want to check into some 4x4 Forums. Some Posters tow up and over high CO passes/off Road and have some interesting tales of overheating. You can add such info to the great knowledge base above from experienced Posters. This Article addresses the perpetual problem of congestion on I-70 at peak times:
Proposed I-70 Congestion Solutions