Weeeeeeeeeellllllllllll, you could always use a "potatoe" bag, or sack.....
Or go to Goodwill/Thrift shop and find an old suitcase, clean it up and use that... You will be so surprised at how the parts spread out when released from the confines of the stuffed box. And if it is still to empty looking for you that is a great excuse to stuff and buy another box of PH parts!