Can respondents save a draft of their answers and come back to finish the survey at a later time?

Save and continue later is possible in Jotform. We have two methods:

http://www.jotform.com/help/227-How-to-Enable-Auto-Fill-Feature

http://www.jotform.com/help/97-How-to-Save-Forms-to-Continue-Later

The first link will allow users to save the data into their local browser storage. Therefore, users are required to continue later using the same computer and browser. 

If you want to give users the option to continue later using any device and browser, use the second method.

Let us know if you have any further questions.

Thanks