Keep the butter in it's original package. I remove it from the box but leave the wrapping on the stick of butter.
Place the butter in the freezer bag, remove as much air as possible and place in the bag in the freezer.
You can store the butter in the freezer for 6 months.
Defrost the butter in the refrigerator when needed.
Notes
Freeze tubs of butter in the containers that they are purchased in. Store them in a freezer bag and store in the freezer for up to 6 months. Defrost in the refrigerator prior to use.