What if Wu not open the door?

The Qing Dynasty of China was started by Wu Sangui open the Shanhaiguan, the Qing army got in. If Wu did not open the door, would the Manchurian set up the court in old Peking?
 
Honestly, I think so. Wu was commanding an army he could not pay, with the capital having fallen to rebels.

What hope did he have to keep the Qing out?
 
Top