UEFI provides a pretty complete environment; it would probably not be too hard to write a .efi program that connected to network and downloads whatever you want from Google Drive (or anywhere else) into RAM and runs it. For that matter, IIRC Linux can already build a combined kernel+initrd into a .efi, so you could make this semi-generic by writing a gdrive.efi that downloaded an arbitrary .efi from gdrive and booted it.
