M.K.
FLY!!! you will be absolutely crazy to drive with a kid that already doesn't like being strapped in the car! no matter how miserable you may be on a plane, it's 2.5 hrs and you are done! if you drive the misery will go on for 2 days down and 2 days back!
we flew down to FL with our almost 15 month old ddaughter last weekend. she is super wiggly, and it was a pain, as she wanted to go up and down the aisle the whole flight, but bringing enough snacks to distract her and going up and down 5-6 times through the flight and we were done! she even slept a little both on the way there and the way back, so it wasn't all that bad.
Make sure you have snacks and different toys, and you'll be fine. if you can, reserve a bulk-head seat (the first row), so that way you have extra room to lay the child on the ground for a nap (couple of airplane blanks covered with your own baby's bedhseet makes a perfect little bed).
have fun, and do yourself a favor and don't fly!