Advocacy Day organization

I have an event where members are coming to the state capitol to lobby their legislators, and I am trying to use a Nationbuilder survey to find out who has appointments with which legislators at what time.  Problem one - if you take the survey and skip a question (because you haven't yet made an appointment), you can't go back and update your answer later.  Question - is there a better tool for what I'm trying to accomplish?  Or is there a way to allow users to see and change their answers to questions that they previously answered or skipped?

Official response from Adriel Hampton

Use member-submitted events under a calendar for the Action Day. http://nationbuilder.com/how_to_start_an_event