It turns out a mistake on your side. So the motion to reopen is off the table.
There is a small problem with the extension filing. Because the approved legal period is passed, your extension filing will not be considered as timely filing. The chance is CIS may deny the application based on this ground. However, you or your hu*****and can write a letter to explan the situation. It is for a good reason.
I believe that your new filling will take similar amount of time to process as the current one.