May I ask what the purpose of your freezer stash is? Are you returning to work soon? Many mothers, both at home and working outside of the home, do fine without a freezer stash, simply pumping on an "as needed" basis. Since you have been struggling with oversupply, I am concerned that if you start pumping twice a day you could end up back where you started. Have you thought about hand expression? Most oversupplied moms find hand expression pretty simple once they're practiced at it, and it usually doesn't cause as much of a problem for them in terms of supply.
HTH. Keep up the good work,