You may continue to renew TN

until your wife's LC and I-140 approved. In the last step, I-485, add your name in her application. So you both can get GC at the same time.

Before file I-485, remember to renew your TN so that you have one full year in hand. File I-485/AP/EAD at the same time, USCIS will send EAD to you after 180 days past.