With the current options, there is no way to allow all students, including students who have not taken the quiz, to review it after the "until" date.
I want everyone to be able to view the quiz and the correct answers, but I don't want new submissions after the due date.
* Not using the "until" field, then manually zeroing out late quiz scores. This requires extra work for the teacher, and zeroing out grades after the fact makes for a poor student experience if they catch onto what is happening. (And someone usually does!)
* Using the "until" field to lock the quiz, but creating a PDF of the quiz with correct answers that becomes available when the quiz locks. This requires the teacher to take a screenshot with the correct answers, make a PDF (or other file format), upload it, and create a new item in Canvas that points to the file and becomes available at the specified date/time. That PDF needs to be kept in sync with any changes to the quiz.
Neither workaround is much good, especially if quizzes are used extensively.
I have a "reading quiz" before nearly every class. The lowest few are dropped from the grade, because hey, things happen. But regardless of whether they take it, students should be able to review these quizzes when studying for tests.
As flipped and hybrid classrooms become more popular, I expect the demand for this feature will continue to grow. There are already a number of people who have requested it:
Show quiz and answers to students who have not submission (archived feature request)
Please strongly consider this improvement. I am disappointed that the identical request linked above was relegated to Cold Storage without explanation.