My wife’s green card expires this Aug. 23. We want to travel abroad this summer from mid June to mid August. We are thinking of returning to the US a week before her green card expires, around Aug 15, and then sending in the I-751 removal of conditions paper work. We would get the I-751 into the USCIS before her card expires. Anyone think she would have a problem entering the US if her green card is due to expire a few days after we return to the US. Anyone have any knowledge or experience with this?

As long as your wife's GC has not expired, she should have no problems entering the U.S. after travel abroad.