Not OP, but I store my TOTP secrets along with all my other passwords in a KeePass database and sync the encrypted database to my devices with Dropbox. All the clients I use to open a KeePass database can generate TOTP codes from the secrets at this point, so I don't use a dedicated TOTP app like Google Authenticator or Authy anymore.

Not multifactor anymore, but also not vulnerable to catastrophic phone destruction or Google account banning. It is what it is.

After the sync, you have exactly two devices that you can use to answer the MFA challenge, instead of one. It's a backup.