seeking your suggestion on 485

an europe global company employing my hu*****and will assign him back to china to work for china branch, but our 485s are pending, should we leave USA? should we withdraw 485? can we apply for GC in Guanzhou China? if after several yrs we come back to US, can we reapply 485 use my present approved 140NIW? welcome any other suggestion and comment, thanks a lot and good luck!