We use a simple Wifi camera (Wansview). It not only has video but also displays the temperature. The app on the our cellphones lets us view the camera.
The camera connects via the Jetpack wifi hotspot in the trailer. As long as the hotspot has cell signal it works fine.
If the cellular is spotty it will also work with campground wifi networks. But then you have to configure the wifi on the camera for each campground wifi. Easier just for us to use he hotspot.
2018 Bowlus Road Chief (24')
TV 2016 Tesla Model X