We fly often with Toto and since she is older now she will hold it for hours on end!! I always give her opportunities to go on her pad, but she simply refuses. I was fortunate that a lady at the desk [at our gate] once showed me a "private" unmarked bathroom and suggested I take her in there. I did and she peed
and pooped on her pad. It was wonderful ... not a single distraction! She is such a little prissy thing, if there is a single distraction, she simply is not going!
Good luck!