Timeline for 10yr green card renewal?

[StoryAngel 4]

I am renewing my GC for the first time (10 yr renewal) and submitted it 3 months before the expiration date on the card. I've received an NOA of Nov 9th and the card expires Jan 21st. I'm concerned I won't have the new card in time - what happens then? Do I need to tell my employer? What about biometrics - I haven't heard anything other than the NOA and when I check on the USCIS website it just says my application has been received.

Additionally I need to renew my British passport which has expired. Do I need to wait till I have my new GC in hand to do that?

Thanks!

[JFH 12,190]

You can renew your British passport whenever you want. It has nothing to do with your green card. 
 

Although your actual card has expired, your status hasn’t so it shouldn’t be an issue for your employer. You can get an I-551 stamp in your passport at an infopass appointment if you wish. 

[StoryAngel 4]

Thank you so much! You have made one of my to do items vanish, and another much easier. 🙃