[j7ake]

iPhone does this with iCloud.

[rohansingh]

How do you login to iCloud without any second factor available?

[mr_toad]

Set up a recovery code (in advance).

https://support.apple.com/en-us/109345

[qingcharles]

And test before you leave!

[jackson1442]

could use a hardware key

[trueismywork]

They can technically ask for your included access as well.