Putting a bottle Jack Daniels into the freezer for a couple of hours or so should be okay.
The average home freezer is about -17 C (-1 F). This is cold enough to freeze your food and ice, but not cold enough to freeze the average bottle of 80-proof liquor.
Water freezes at 0 C (32 F) and the freezing point of pure ethanol alcohol is -114 C (-173.2 F). Alcoholic beverages are a mixture of both alcohol and water (in some cases, sugars and other additives as well) so the freezing point of your alcoholic beverages is somewhere in between.
The exact freezing point of vodka, tequila, rum, whiskey and liqueurs (as well as wine and beer) is dependent on its alcohol by volume (or its proof).
The Freezing Temperatures of Alcohol
40 Proof Liquor
20%: -7 C (22 F) Includes many low-proof liqueurs like Irish cream. If left in a really cold freezer too long, these may get slushy, but this is rare.
64 Proof Liquor
32%: -23 C (-10 F) A liqueur like amaretto and a flavored whiskey like Fireball would fall in this range. These should be okay in the freezer.
80 Proof Liquor
40%: -27 C (-17 F) Includes most standard base liquors like gin, vodka, whiskey, etc. You're clear for the freezer! - Is Your Beer, Wine, and Liquor Safe in the Freezer?