I am working on an email that includes a table that is 3 cells across, for desktop. My goal is, on mobile devices, for the center cell to pop up above the other two cells and expand to fill the width of the email. The two cells that were originally on either side of the center cell should then fill half of the email width, each. I've experimented with the content stacking techniques from "http://labs.actionrocket.co/stacking", but have not been able to achieve the desired results.
By way of very crude example:




Any suggestions? Has anyone already conquered this challenge?

Thanks for your help!