Place the cream cheese and sugar in a large mixing bowl. Beat with an electric mixer until smooth.
Add the eggnog, rum, and nutmeg. Beat until smooth and all ingredients are combined.
Using a spatula, gently fold in the whipped topping. Place half of the mixture in the graham cracker crust. Use a spatula to spread it evenly.
Lightly drizzle half of the caramel over the top. Pour the remaining whipped cream mixture over the top (about ½ cup of the mixture may not fit in the crust—just leave any mixture that doesn’t fit in the bowl). Use a spatula to spread it evenly.
Drizzle with the remaining caramel. Place in the freezer for at least 5 hours, or until firm.
If desired, put a few toothpicks in the pie and cover the toothpicks with plastic wrap. Putting plastic wrap directly onto the pie will mess up the caramel drizzle.
Remove from the freezer and immediately cut into slices.
Place on plates, and garnish with a sprinkling of additional nutmeg, if desired. Put any remaining pie back into the freezer immediately.