Here is the full stock OTA image (not incremental) of Android 5.0.1 Lollipop for the NVIDIA Shield Tablet (LTE & Wifi-only) that can easily be flashed using a custom recovery like TWRP or Philz. Just pick up the appropriate update package below and flash it right away.
NVIDIA Shield Tablet Android 5.0.1 OTA Zip Package [Wifi/LTE]
NVIDIA Shield Tablet is officially getting the Android 5.0.1 Lollipop update via OTA around the globe as a part of the new Software Update v2.1 that weighs around 90 MB. You can download the Zip file of this OTA for both LTE and Wifi-only variant via the direct download links given below and flash it manually using your stock recovery.