maintaining context if a workflow is interrupted

I have a design challenge in which a site visitor will be asked to transit from page to page by clicking buttons. On each page, the visitor will be asked to fill out a form (e.g. answering questions for the site owner). If the visitor interrupts the flow by leaving or abandoning the flow, what would be the simplest way of having the visitor resume without starting from the beginning? Would sending an email with a link and some parameters at the conclusion of each step be easiest? Should the visitor be required to register on the site (perhaps a point of resistance)? If the visitor gets to the end of the workflow, they will be invited to schedule a call with the website owner. Your thoughts are appreciated. By the way, I could not figure out how to use your new live chat. No one seemed to respond. What happened to the scheduled live sessions?