Send picture from ESP32CAM to ESP32

[Pcborges]

Hi, I am working in a project where I need to transfer an image from an ESP32 to an FTP server via GPRS.
The cheapest alternative I found was to use an ESP32CAM to take the pictures, send them to the TTGO T-SIM S7000G to be sent via GPRS to the FTP server. The TTGO does not have many pins left. WIFI is not available and the project is to work on batteries and solar panels.
The project already have an OLED display and a temperature monitor sharing the standard I2C bus.
What is the best way to have these pictures transfered from the ESP32CAM to the TTGO?
Is it possible to make this transfer using I2C?
The OLED display and the BME280 are only used on request and would mostly be silent.
Thanks in advance
Paulo