While they have that option, they don't have to finish without stopping.  If they need to pause and come back later, they can simply click the Save Draft button at the bottom of the page.  Any work they've done on that Hoop will be saved and they can resume when they're ready.

NOTE: Saving a draft for later DOES NOT move the deadline for that Hoop, so they will still need to get it done in the total time allotted for that Hoop.