I don't use the widget, but it looks like the widget sorts the tasks in the same order as the list on the web version and the Android version. If that's the case, then you should be able to sort the list by Due Date in one of those versions and have that reflected in the widget.

I have my primary Smart List sorted by Priority and then by Due Date, and grouped by List. When I add that as a widget, it's sorted the same, though it doesn't show the group names.

Nope that is not the case. I picked the setting "sort by due date" within the app but the widget is sorting by priority .

Can you remove the widget, sort by Due Date, and then create the widget again? Does that make any difference? Or is that what you've already done?

I stopped checking this thread 3 days after I posted it but I guess I stopped prematurely. I removed the widget and set it up again. This time I saw a new setting that let me only show things due today. I think my problem has been solved. I appreciate your suggestion!