TN Status : Apply Where? Add family members later?

Hi all! I have some questions on the TN Status, hoping someone here can help me out:

-A TN application 'packet' is being prepared for me by my employer, but where do I actually go to apply for the TN once I receive it? Do I need to drive to the border? Or is this something I can do on the day of my flight at the airport?

-I have a family, but they will not be coming with me right away (they will be remaining in Canada for several months). Is it possible to 'add' them to my TN status at a later date?

Thanks in advance!

-I have a family, but they will not be coming with me right away (they will be remaining in Canada for several months). Is it possible to 'add' them to my TN status at a later date?

I started work and my Daughter followed me a month or so later. My Immigration Attorney had prepared a petition letter for her to present at the POE(driving) on her way to the airport to catch a domestic flight. It had a copy of my visa and my passport ID page attached and she had no problem getting her TD. No matter when they follow you, their visas will expire the same day as yours.