Instead of Google Authenticator, I use Twilio Authy. It syncs the 2FA code across my devices. I keep a backup device at home.
Sure, it's not the most secure way but I trust this over carriers securing my number.
Sure, it's not the most secure way but I trust this over carriers securing my number.
And
"By default, each of Twilio Authy, Yandex.Key, and Salesforce Authenticator also relied solely on SMS OTP to authenticate users during recovery, but did encrypt TOTP backups using a key derived from a password before uploading them to the cloud. To compromise the backup, an attacker who hijacks the phone number will still need to conduct an offline attack to guess the backup password.
Edit: looks like you can fall back to SMS (along with backups password) to add a new device.