As mentioned on this thread, if you renew your TN status via regular mail, your TN is extended up to 8 months until the new TN is being processed ( i believe the average time frame is around 2-3 months). If you apply and its taking long time to process and your driver license expires, how do you get your driving license extended? they look at your i-94 to grant you you your license, will they do a temporary extension based on what i tell them?