I found the following:
Responsive Durandal dialog
However I don't see any documentation on making the dialog responsive in 2.1. I have a dialog that extends in height as the user selects stuff - eventually the dialog gets taller than the viewport and there's no scroll or anything so it's a total mess on mobile devices. I've tried using the "reposition" functionality from the docs but this doesn't seem to do much. Any advice around this would be much appreciated.
dialog.show('viewmodels/doThis', { data: data });
addEditDialog.context.reposition('doThis'); // doesn't help