If you go to the external link, it says the following on the Miele manufacturer's page:
Freezes at ambient temperatures down to -15 °C - FrostProof:
FrostProof ensures that the appliance can be used even at ambient temperatures as low as -15 °C. If the temperature falls below +10 °C, efficiency is ensured. The unit can be used accordingly in unheated rooms, such as the garage.