How do I ask a single question after the survey has been completed?

I launched a survey that lacked a crucial question and I would like to add that question now. We have already had a few responses so we would like to be able to open up the survey again, including to those who have completed it. For those that have completed it, is it possible to only ask the one new question when they reclick the survey link? There should be a record of who completed the survey given if they have already completed the survey and they re-click the link there is a message that says ‘You have either already completed the survey or your session has expired.’