You can try CP

to get your GC. File Consulate processing instead of I485. You can google the form number. In this case, as long as your I140 was approved, you can wait till your chance to get an interview in Guangzhou U.S. consulate, to get your immigrate visa there. So once you enter the States, you are GC holder.

Immigration involves two steps, one is immigration petition(I140, or I130 etc). The other is adjustment of status. This step can be through by I485, or CP. Either way will be fine.

So you still have a chance to get your GC.