Obviously my advice doesn't pertain to your main point, but as a person who's been to 80+ countries, and very experienced with this, my advice is only use carry on, it's not worth the risk. Buy the biggest bag you can that's allowable as a carry on and use that. I've had only a carry on whilst travelling for 7 months straight, and it worked out fine for me, pack light and wash your clothes at your hotel/airbnb.