Keep your insulin cool in a cool bag or Frio wallets or ask the airline if you store your unused insulin supplies in the cabin fridge. I would get a letter from your gp and if they charge ask your dsn or consultant for one, they won't charge and will happily provide one.
Also take a copy of your repeat prescription in case your luggage is stolen, that way you can present it to a Dr or Pharmacist and purchase new supplies over there.
Not sure on the fluid restrictions but the airline you are travelling with will clarify matters, if your unsure about anything give the Diabetes UK Careline a ring, they have some excellent advise for type 1's travelling abroad.