Have not traveled with such an old cat. I agree that just as with a very old person, long-distance travel is going to stress him - you have to balance that against not being able to take him at all.
I did learn a lesson about traveling with cats when I was a teen. My parents and I moved from NJ to FL with two cats. One was 10 years old, the other about 6. My dad did all the driving. But being in his 60's, he divided the 1250-mile trip into 3 days. Mom and I babied the cats in their carriers, and in the hotel room, so all was well as far as litter behavior. But we had a bad scare when we had to leave the cats in the car while we stopped for lunch. The poor things refused to drink from the water dishes I put in their carriers, and got dehydrated far quicker than we expected. We came back to find them lying listlessly in their carriers, panting with their tongues hanging out.
After running the AC like mad in the car and coaxing the cats to lap water from my hand, they did revive, but we were so scared that for the next 2 days, we only grabbed fast food for lunch and brought it back to the car to eat.
I think in your case, I would drive, but divide the trip into 2 nights. Somebody needs to baby the old fellow in the car and in the hotel, and I mean baby, even if it means letting him lick water and food off your fingers or his own paws. I think he will benefit from being fussed over. Old people seem to.