I'm in Hong Kong, where it's both hot & humid (30 degrees Celsius, 95% humidity) & I think the AC in these sorts of places tends to be a little crazy. I think you should plan outfits where you can layer up BUT they also look good without the extra layers. Accessories will help to change up the looks without taking much space in your carry-on. Here's a suggestion for 3 days, but of course you can change it up as you see fit:
ITEMS:
-Black Blazer (if you want to wear flares, it might be better proportion-wise to do a cropped Blazer rather than a longline one)
-Pashmina (you can drape this over your shoulders or loop it at your throat in the AC, then tie it onto your handbag as an extra pop of colour when you're in the heat)
-Cropped flares (I'd recommend a pair in a seasonless fabric, but the cropped length may mean you'll need to wear them with heels to look professional, if you're OK with that?)
-Heels
-Accessories (I was thinking maybe a long necklace to temper the width of the flares, and add some vertical integrity without adding bulk. You could also add a belt to make any tucked in tops with your flares look intentional and professional).
LOOKS:
-Blazer, Silk shell blouse, Crops, Heels
-Pashmina, Flutter sleeve blouse, Crops, heels
-Long necklace, Flutter sleeve blouse, Crops, heels
-Pashmina, silk shell, etc lol