score:5
Some ideas.
You don't have to take the whole file with you, just a file with that specific password.
You can obfuscate the password (whether on paper or in a file). What I mean is that, for example, you can write a b
instead of an a
, and a c
instead of a b
etc.
You can use an offline password manager and remember some password/passphrase.
You can encrypt the file.
If you choose to use a password manger or encrypt the file, you can store that new password on paper and keep it separate from the iPad, and can obfuscate it as well.
Perhaps worth reading - an answer about storing passwords by a top contributor on security.stackexchange.