If the printer runs a Marlin variation as firmware (Ender probably does), you can run octoprint on a Raspberry pi or more powerful stuff. Running in docker should be doable, you just need to route the serial-usb connection into the container running ocotoprint. Klipper user with Mainsail on a RPI4 here, no experience with a dockerized octoprint.

The most slicers have some calibration prints to tune flow/temperature etc. Do them before starting that 9 hour print job…