ITA with Didi- I found bottles on international flights very easy. I took my clean, empty bottles on board (so as to avoid the on-board fluid restrictions), and my little formula wheel. When Peter was hungry, we just went to the little kitchen bit and they would put some hot water in and some cool water in up to whatever level you need, so its just the right temperature. Put your formula in and you're good to go.

We had more problems with heating bottles on internal US flights- they wouldn't give us hot water due to safety restrictions, grr. They ended up putting hot water in a sick bag and then standing the bottle up in there to heat up!!!

I hope this makes sense, we just got back from the States this morning and I am soooo dead!