I wish Apple would introduce a "Border crossing mode". Not gonna happen.
https://support.1password.com/travel-mode/
It will only allow vaults marked "safe for travel", everything else is removed from device. Once you get past the security theater you can re-enable the non-travel vaults from your computer.
Here's some info on it: https://www.digitaltrends.com/mobile/how-to-use-android-9-pi...
Read the EFF Digital Privacy guide for the Full Monty: https://www.eff.org/wp/digital-privacy-us-border-2017