I upgraded my laptop to Bionic but the display failed to work. I was able to get into the grub menu on the install media and entered nouveau.modeset=0 which has worked in previous versions of Ubuntu but with Bionic I get a blank display. Sound works and I can hear Ubuntu start.
I was able to install Bionic by connecting a monitor to the HDMI port on the laptop and then hitting the FN+F9 on my laptop keyboard to switch the display to the main screen and could install fine. Once the system rebooted, I hit enter on my keyboard and then blindly typed in my password and the remote display came on again, and I was able to hit FN+F9 to go back to the main screen and finish setting up the laptop. I installed the NVIDIA proprietary drivers, which I have done in the past versions of Ubuntu to get the laptop display to work properly, but this didn't fix it. I also removed the nouveau.modeset=0 from the /etc/default/grub configuration and re-ran sudo update-grub and rebooted and still, the local display does not work.
I was working on this issue in the past when Bionic first released (LP:1761261) and another user found a patch for the pincntrl that does fix this issue.
Looking at where the patch came from, there are known bugs with the patch with Google Chromebooks, so this patch has never been pushed upstream, and it does not fix every issue with the laptop. For example, the brightness controls on the keyboard do not work as well as the calculator short cut or the ROG buttons (which I don't expect ever will work since they are designed for the ROG App in Windows OS)
It looks like the display issue in Bionic on the GL703VD laptop has been fixed with the release of the 4.15.0-25-generic kernel.