I don't think you will be approved either at border or from USCIS to extend your TN (so does your spouse's TD), since you have submitted I-485.
You may try to apply TN at border WHEN you have AP handy. You may get it at CBP's mistake, or you may still get in by an AP in case of a denial.
If your TN (TD) expires, you will be in AOS. When I-140/485 is denied, you will need to leave , which is what "1mm" is experiencing.