Multi-factor authentication won't work while abroad

Just tried to log on to my Momentum portal online, and was forced to set up multi-factor ID before I could proceed, which I then did. Turns out, however, that an SMS sent to one's registered cell number is the only mode of secondary authentication currently supported (no option for biometrics or email as an alternative) - which left me wondering: What happens when you travel? Will you be forced to roam at enormous cost just so you can receive Momentum's SMSes? I phoned customer support, but was basically told that you'd have to wait until you got back to SA before being able to access your Momentum portfolio online again. Unbelievable. The mind truly boggles.