Max paranoia: Backup your data and apps to a fully encrypted data source you trust. I.e. seedvault.. optionally you can practice restoring a backup on another phone .. a untested backup is just hope. And if your brave, factory reset.. once you arrive and are happy and safe, restore the backup

Reasonable: Prepare a second travel only phone: taxi apps, voip, travel email, secondary im

In the airplane-

Disable biometric unlock unless you have multifactor already (gos)

Turn off your phone before landing, and only turn it on after clearing customs. If your phone leaves your custody at any point then it's compromised and don't turn it on or login.

Be polite, respectful, and efficient in the airport.