For milder regions, adding a layer of mulch on top of your pots or wrapping them in fleece can be enough to ensure your gladioli last the winter.
In colder climates, try moving the pots somewhere frost-free such as the shed. Or, if you want to use the pots for winter plants, lift the corms, dry them out, and store them in boxes or trays somewhere dry and cool – similarly to dahlias.