Save the data, tell them about it in your privacy policy (i.e. that you remember that data and how you have in mind to use it), and add a "delete account" button that deletes that data.
Maybe show a notice just below the address input fields that "we remember your address for a while, this is why" and link to the relevant section in the privacy policy.
Maybe show a notice just below the address input fields that "we remember your address for a while, this is why" and link to the relevant section in the privacy policy.