Most people seem to be unaware of what the Denali Highway is. Many apparently think it is the park road within Denali National Park, or even Alaska Route 3, the George Parks Highway, typically used to drive to Denali.

For information on driving times on the real Denali Highway, just look them up on Mapquest or similar on line services. If they route you another way, just manipulate the inputs to show Cantwell to Paxson, and at some point you'll have your information. Driving times won't really vary much for different kinds of vehicles. Mapquest shows 5 hours, 11 minutes, for Cantwell to Paxson; this can be determined by checking the "shortest distance" option.

I'm planning to drive this route this summer with a rental car, without worrying too much about rental car restrictions. I'm looking at an 11-hour drive time from McKinley Park to McCarthy, which is further than what you have in mind.