I haven't flown from DFW, but I did fly from a Chattanooga airport.
They sent my daughter and I through a different detector. She was about 18 mos at get time, and I carried her through. The air pressure didn't bother her at all. The airline we flew with actually upgraded us to the extended seating area for free so we could have het extra space. It was really nice, and we had a great experience. :)
I have also gone on LONG car trips with her. The longest was a 3 day trip when she was 6 months old. She handled it pretty well... But it was pretty inconvenient for us. We tried to travel at night, so she would sleep most of the time. Even with that, we still had to stop every few hours for feeding, diapers, etc. we also had a surprise tornado come through... We thought it was just a bad storm and hung out in the Walmart parking lot for a few hours until we thought it would be safe. (The forecast was for a slight chance of showers. Lol.) We also wound up with a flat tire on that trip too. It was really annoying.
I would fly in your situation... Save yourself the mileage and time. Lol.