I always thought Anna was rich enough to have her own private plane, to not have to worry about taking a commercial flight.
So she is stumped by airport travel? Somehow that knocks her down a peg or two for me. After all, Grace Kelly mastered the 'how to look comfortable and stylish while traveling the globe' look in a time period of corsets and longer skirts. If she can do it, there's no reason Anna can't come up with a creative, stylish, comfortable airport outfit. (Seriously, Anna. Methinks you just want to keep your precious reputation as an impeccable, inaccessible ice queen fashion goddess who doesn't exist in the real world.)