Here is a smart security camera that works well even in WiFi challenged environments. The eufy 4G Starlight Camera uses an AT&T data-only SIM card. It has 2K resolution and lasts up to 3 months on battery. You can optionally power it with a solar panel.
The eufy 4G Starlight Camera has AI human detection to reduce false alarms. It records video to its 8GB eMMC local storage. It has a GPS help you locate the camera if it is stolen.