To make ahead, the whole pie can be frozen unbaked. Assemble and wrap the entire pie in plastic wrap, followed by foil. Alternatively to foil, place the plastic wrapped pie in a large (2 gallon) ziptop bag and remove as much air as possible from bag. Unwrap pie and bake straight from the freezer at 350 degrees F for 1 1/2 hours (90 minutes). Will keep in the freezer for 3 months.