Thank you for the pointer. I had the same question, and it primarily goes back to pretty terrible UI design. The obvious place to look for downloading student submissions is the Grades screen, not the assignment screen. Even within the "Quiz Statistics" screen, it is not readily apparently that "Student Analysis" would be the place to download all student responses. Perhaps this is Canvas trying to force any and all activities to take place within their system by designing such counter-intuitive offline work options. If not, hopefully someone at Canvas will review these questions and recognize the counter-intuitive nature of their current design. Until then (and given the timing of the original and my message, don't hold your breath), thank you for helping those of us who couldn't readily fathom this bizarre access location.