StopICU is correct. You can get the camera to start up (while at your camper) using the hotspot on your phone. (Wyzecams need to chit-chat with WyzeHQ when they boot up, or they become unhappy). Configure the camera to connect to your phone’s SSID. (this assumes that you have cellular data coverage at the camper). Once the camera boots up, you can configure it for local recording to SDcard on the Advanced Settings page, either Continuous or Record events only. Be sure to turn off Event Recording (ie, disable Detects motion and Detects sound), since the camera won’t be able to send any video to the Wyze cloud without a permanent internet connection.
Once the camera is so configured, you can turn off the hotspot, and depart the camper, taking your phone with you. The camera will continue to record to the SDcard as long as it has power. But if the camera loses power, even momentarily, it will stop recording. And won’t resume recording until it is able to reconnect to WyzeHQ.
When you return to the camper the following weekend, re-enable the hotspot on your phone. The camera should find the phone’s WiFi and automatically reconnect, though it may take a few minutes to do so. You can then view whatever was recorded on the SDcard with the View Playback button.