Colorado's closest Pac-12 game is a an 8 hour drive to SLC. Second closest game is Tempe, which is a 13 hour drive from Denver.
In the 2023 Big 12. They'd have the two Kansas schools, Provo and Lubbock, all in under 9 hours to Denver.
Plus you get Stillwater is 9 hours. ISU in 10 hours. TCU is 12.5. So 7 schools at 12.5 hours of driving or less. Versus 1 in the Pac 10/12.
CU would have direct flights to SLC, OKC, DFW, KC, DSM, Lubbock, Houston, Orlando, Austin (Depending on how you want to get to Baylor), Cincinnati, and Pittsburg (WV)