Travelling with formula fed baby

Just bring empty bottles on board with prepacked milk powder in disposable milk bags. When onboard, can ask flight attendant for water to make milk on flight. Sterilise wise, can use hot water to soak. But tbh I never sterilize when overseas (just wash and make milk) nor buy bottled water to boil, my lo is still alive and kicking (no diarrhoea or anything) 😂