That change in altitude from sea level in the SF Bay Area to 9,000 feet plus in the Colorado mountains can be quite taxing on us older folks. Occasionally, I will fly + rental car the trip "up" in 5 hours total transit time, but may have difficulty breathing for the first 3 days in the mountains thereafter.
Driving my own car over 2 days (20 hours of engine turn time) or riding the CZ + Greyhound connection (29 hours total travel time) helps very much in gradually acclimating to the altitude increase, so I am better able to function immediately upon arrival in the High Country.
But for distances beyond 1300 miles, unless I have enough AGR points to cover the train, it's fly, rocket, fly; up up in the sky.
Driving my own car over 2 days (20 hours of engine turn time) or riding the CZ + Greyhound connection (29 hours total travel time) helps very much in gradually acclimating to the altitude increase, so I am better able to function immediately upon arrival in the High Country.
But for distances beyond 1300 miles, unless I have enough AGR points to cover the train, it's fly, rocket, fly; up up in the sky.