@CCTVOrGrandma 

Hi,
The Tapo C200 uses data when it's activated but not recording for motion detection, for example, it needs to sync time and date with the NTP server via the internet, and it consumes internet data when you stream it remotely, etc.

If you insert a microSD card into the C200 and set detection features and storage settings correctly on the Tapo C200, usually, the camera will continue to detect and save recordings to the SD card even if the Tapo C200 has no internet access, but the remote control feature is still not working without internet, and you can check if this usage scenario can meet your inquiries.

Below are the instructions to set the motion detection feature, and how to select microSD card.
How to use motion detection function of my Tapo camera in Tapo app? 
General Information about using MicroSD Cards with TP-Link’s Kasa or Tapo Cameras?
 

Best Regards