I went to Thailand on Jun with my 1 1/2yrs bb for 5 days trip. I brought 3 bottles of water, bed sheet, pillow, doll, bottle congee & some stuff. When the plan take off, either you can let his drink the water or 奶咀.
Most of the hotel will provide the baby cot (you can request in HK through your travel agency). But my baby only want to sleep with us.
In Thailand, it is really so many mosquitoes. Beware of this.
Remember to get the medical from your paediatrics.