That's pushing it a bit to get to C66 for 20 minute close. Doable just about if you run and you're in 1C, but if you arrive from 22F you won't make it, and arriving at an international stand means you've got no hope of making A9 in time, let alone C gates.

(P.S. why not allow dom arrivals at int stands who are connecting to int to exit into the airside terminal directly, surely the gates could be used to conform people. You could even just auto-confirm anyone on board an incoming DOM plane when the doors open)

However DOM-INT should be 15 minutes less than INT-INT and since the recent enhancements 20 less than INT-DOM. 45 minutes DOM-INT seems fair enough. Even from the back of the plane you should be comfortably in the main terminal for T-35.