Zest end of both lemons. Cut 1 lemon into thin slices.
Remove neck and giblets from chicken cavity and discard. Pat chicken skin with paper towels.
Place chickens, breast side up, on a work surface. Gently loosen breast skin by working your fingers between skin and meat. Slide lemon slices under breast skin of each chicken. Put one chicken into each freezer bag.
Divide lemon juice evenly over chickens. Juice remaining lemon. Remove seeds and divide juice evenly over chickens to each bag.
Seal and gently shake each bag to combine contents. Freeze. Food will stay at optimal quality for up to 4 months in freezer.