I stressed about this before my surgery and in hindsight I can honestly say that both have their advantages. Your doctor will want you to stick around for a while. I think it was 4 days and after a swallow test at MBC, but ymmv. Either way you go I think the biggest thing to remember that you will not be eating much at all at this point. A few tablespoons of sugar free Jell-O was a big deal. What gastric distress might arise will be correspondingly small. Also, on travel day you can just play it very safe with what you take in.
Driving: You are in control. You can drive like a daemon but if something happens, you can hang out at a restroom for as long as you like. Most cars are pretty comfortable and with the addition of pillows and fluffy blankets you can position yourself to the best. Maybe you could sleep spread out in the back seat most of the way home.
Flying: Fast, but jarring. Remember it may be a 90 minute flight, but entirety of the whole trip to and from the airport, check in, security, waiting, boarding.... And during all of it you have no control, you meet their schedule or else. I got a wheel chair and I was glad because I walking slowly enough that people would try to get around me and often jar me as they went by. Also, there isn't a lot of choice for how to arrange your body in the airplane seat. But pain pills can be your friend and the flight became nothing but a small annoyance after I took some strong ones.
I had no gastric issues on the way home and that was with a ds. It was just a 6 hour flight, but It took over 12 hours to go from MBC to home. If we would have driven it would have been 24 hours, but we would have split it up into several days. I had been looking forward to rewarding hubby with a play day in Los Vegas whilst I snoozed away in a hotel room.
Honestly, you can make either work best for you. And although the veterans are wise to warn of issues that might arise, everybody that left with me or I saw leave during my week at the hospital was more than fine. We were all taking 5 to 10 walks around inside and outside the hospital every day. My travel day was the least amount of walking I had done in days. Our bodies were more than ready for the trip home.
It's just miles and miles (well, kilometers and kilometers, here) of farmland in the middle of nowhere. Not like US highways where you have a rest stop or a McDonald's every 20 miles, at least. So I'm not sure which is the lesser of two evils - the flight MIGHT be since it would only be one session of no bathroom access instead of multiple ones. 
