In college, I used to drink a pot of coffee for cramming sessions then sleep like a baby when I felt like it.

As I aged, things like light sensitivity, noise, room temperature, and circadian rhythms, caffeine sensitivity, etc. became increasingly important.

Everyone is different. But it's something to consider before you "lock in" to a multi-time zone commute for overseas travel. You will age, after all.

The "wearables" that are available are pretty eye opening just for DOMESTIC overnights, much less international stuff.