I just flew to Florida with two seven foot poles in a Bazuka tube thingy you can buy from cabelas for like thirty bucks. I only think it goes to eight feet though. Nevertheless, I checked it, and those morons from Baggage safety took it apart in an inspection, and put it back together wrong.
When they reassembled it they didn't take the care to do it right, and the collapsable tube was able to collapse. Mo'fo's broke my tip guide. I have no recourse as well because they do not cover damage to "sporting goods".
So, I think you have a good excuse to go build a two piece, get a rod tube, and carry it on. I wouldn't do it any other way with regulations the way they are.