Although it's not covered in the basic setup, I'm fairly sure you can set up your own controller locally and set the adopt URL on the AP (via ssh) to match. Thi

Although it's not covered in the basic setup, I'm fairly sure you can set up your own controller locally and set the adopt URL on the AP (via ssh) to match. This process requires no internet beyond downloading the controller software (they maintain a .deb and provide source).