1. Buy a reputable bottled water. In Bali, I don't think you can find "Evian", but "Aqua" is a good brand. According to me, as long as they're sealed, then it should be fine.
Boil the bottled water with the electric jug usually provided in the room, keep in a thermos - it's a good investment to get one since you don't know for sure the quality of the water or kettle used, even if they boil it for you in the restaurant.
Then bring another bottle of water (of room temperature) to mix with the formula.
2. I used to the sterilizing tablets while staying in the hotel. Just buy a cheap PLASTIC container over there, then you can leave it in the hotel (if can't fit in the suitcase) when you leave. You can't use metal container when using sterilizing tablets. Rinse the bottles with boiled tap water (to get rid of the chemical smell/taste).
3. Beware of the mosquitoes! Bring spray/cream recommended for young babies. Bring 2-3 long sleeves and long pants, just in case you need to go out after dark. Mosquitoes there are vicious and merciless in the night time.
Hope this helps
