Is there any way to change to location of the Game folder to a secondary drive with more hard drive space? I figured out how to tell GOG Galaxy where I want new installs to go but is there any way to move a currently installed game folder. I don't want to have to uninstall the game then reinstall it then start over from the beginning.

Just cut and paste the installation folder?
Works with installations done with offline installers at least, no idea if it's the same for installations done through Galaxy.

you will have to verify the game and restart your system after moving the files... galaxy only not off line installs