Curious, so I googled: All 80 proof vodka freezes at a temperature of -24 degrees Celsius(-11,2 degrees Fahrenheit). Sometimes the freezer is a little bit colder than this or the bottle is placed close to a freezer element and it may actually freeze.
Freezers should be kept at a maximum temperature of zero degrees Fahrenheit in order to maintain food quality. Even lower temperatures, ranging from minus 10 to minus 20 degrees Fahrenheit, are recommended to maximize the lifetime of frozen food. Freezer temperatures above zero are not adequate for frozen food storage.
OP needs a higher proof Vodka!!!