You can do a netinstall if you can can put the kernel and initrd from the netinstall CD somewhere where GRUB or some other bootloader can load it. But it would have to be an unattended install since you have no console access. I can’t comment on that as I have no experience, and of course if the install fails you have to start from the beginning if the kernel and initrd were overwritten during the install.
The only way I would try, would be to build a Virtual exact copy of the remote system on another machine, install openSUSE on the Virtual copy, then restore an image of the Virtual copy to the remote. Even then the Virtual copy would need to have the same hardward as the remote, or use generic drivers.