Kind of depends on how much you want to stay married.  One of you is going to get to drive the tractor while the other one does the stacking.  Guess which job you should volunteer for.  If you have to pick it off the ground by hand, you really should try to get a couple of high school football players for the day.  It just works a lot better if you have two on the wagon and one walking beside.  Trade off every load.  Can you find someone with a New Holland bale wagon to gather it for you?  Do you have a skid steer?  A careful operator with a manure tine bucket can do a lot of consolidating the bales in the field which can save some time loading the wagons.