We took our 7 month old to Madeira last year.
MILK: Took aptamil cartons and poured into his bottles just before security. I was asked to taste it. It was fine. Also took Ella's Kitchen pouches - clean and easy to close with no mess. We bought aptamil tub at the pharmacy, airside at the airport but we found Madeira stocked it which was just as well as one tub only lasted just over a week. He had more milk than food as he tends to eat less when hot.
NAPPIES: We took some nappies for the first three days and swim nappies. Found portugal's 'own' brands did the job well.
FOOD: We took snacks and ella's kitchen pouches and found that in Protugal, parents tended to make their child's own food at home and ask restaurants to warm it. It was this that made us go down the baby led weaning route - best decision made ever!
ROUTINE: We made the mistake of wanting our son to go to sleep at 7pm (still too hot) and sleep soundly in his buggy whilst we ate at 9pm. We learnt that our son would dictate what he wanted and it was far easier for us to allow him to tell us when he was tired.
AIRPORT: Go through 'fastrack security' if you can. Takes the hassle out of the long queues. The buggy can go with you to the gate and if you board the plane from the tarmac (i.e. you need a bus or a short walk to the plane's steps, you can take it as far as the steps. It goes straight into the hold and in Madeira - can differ elsewhere - you collected it first thing when stepping off the plane steps. Take a baby carrier though for the flight because if you cannot get your buggy until you get your luggae off the carousel, it can be a 30 minute nightmare holding a baby. We took infant car seat too and it went straight to 'over sized luggage' when checking in.
TOYS: We took small, hand-held toys. Also helps if the place you are going to has a creche that families can use. It was our son's favourite place and also good place to go whilst taking refuge from the sun between lunchtime and 4pm.
FLIGHT: Our son slept on take-off! It was a 7:30am flight and had been awake since 5:30am and was 'woken' for his car journey at 4am so slept/awake every 40 minutes on a 4 hour flight. Journey back, not so much sleep - it was an afternoon flight!
Good luck! We're going bck to Madeira in 5 weeks - with a now 19-month-old. i have heard toddlers are a nightmare compared to babies!!!!