I think this should work to disable the notification and prevent the update from d/l'ing, but, you will need root and seperate software. Going to test it myself now and will update shortly.
It was originally written for the Nexus 7, but, the D801 uses Google Services framework for updates also, which is why we can't just 'freeze' the update app like you can on other carriers. The original post was made here...
http://xdaforums.com/showthread.php?t=2429820
Here is how I disabled the upgrade prompt on the Nexus 7 grouper wifi 4.2.2 - You of course need to be rooted.
Get Autorun Manager from the market -
https://play.google.com/store/apps/d....autorun&hl=en or
http://goo.gl/xdLmO
Launch Autorun Manager, select Advanced mode.
Click the wrench, check off Show system entries and Enable system app disable.
Click the refresh icon to reload the process list.
Search for "systemupdate" and open the Google Services Framework entry.
Uncheck com.google.android.gsf.update.SystemUpdateService$ Receiver
*For me, this was the very last one in the list under Google Services Framework*
Reboot your *phone* and be nag free.
Edit - Market update notifications for apps is functioning normally.