NIS 2012 Updating multiple PCs question

Ok here is my story. I run NIS 2012 on 3 PCs in my household. Love the 2012 version. What I need to know is very simple.

 

We have bandwidth caps on our internet cause we live in the middle of nowhere. What I would like to be able to do is update 1 system over the internet and then pull the updates from that computer to the other computer. Is this possible? Is there something I can do to make this happen. I have to watch my bandwidth carefully and with 3 systems updating believe me it adds up. Having a solution to this would help immenselyf. Thanks for your time!

-Thermite