Just a quick update.
I left Denver at 6AM local time, arriving back at my Southern California place at 9:30 PM. Counting one hour of time difference, I made the 1,000-mile trip in 16 1/2 hours, and that included one hour lost in Las Vegas for refueling and buffet dinner at the Luxor, and one hour lost in the heavy traffic leaving Las Vegas for California.
Since I had been well rested the previous evening, I did not feel tired at all. My car is extremely comfortable, and was a perfect companion for this long drive, which was the longest one-day drive I ever did. My previous record was way back in 2000, when I drove from Concord in the San Francisco Bay Area to Tucson, Arizona, a distance of about 850 miles, over 13 1/2 hours.
Denver locals had told me that when driving between Denver and Southern California, it's easier going westbound than going eastbound. I found that to be very true - because the hypoxia of 11,000-foot-high Eisenhower Tunnel happens at the beginning of the drive when going westbound, rather than at the end of a very tiring day during the eastbound drive. Also, going westbound, I gain one hour from the time difference.
I fueled up in Fruita, just west of Grand Junction, to prepare for the long hop across Utah and Arizona. When I got to Mesquite, the first Nevada town, I was still showing 90 miles or so of cruising range on the trip computer, so I continued to Las Vegas, hoping to refuel at a Costco, but that Costco's gas station was now permanently closed, and I had to run on fumes to refuel on Flamingo just east of the Strip. I had driven 490 miles without refueling!
I'm very glad to have made the drive. This trip was less about Denver, and more about getting there and back; the drive was indeed very scenic! I do hope for even longer drives ahead. If Denver can be done in a day, then I can get to Chicago in two days, or New York in three days.