Use OTP via "Google Authenticator". But instead of using google authenticator, use Authy, which is a similar app, but syncs the OTP seeds across many devices, so you can use any device you own.
If you don't want to download a separate app just for OTP codes, many password managers (like 1Password, which I use) can also store and sync OTP URLs/seeds, and can fill in auth codes like this along with your password. Highly convenient!
If the password manager is then not forcing 2FA, wouldn't this defeat the security gains from going two-factor?