Each of the 26 clues represents a 6-letter word. For each of those words, it is possible (in only one way) to replace the first two letters with a single letter to create a 5-letter word (“Santa’s lead reindeer has to work hard enough for two”). (The title of the puzzle is another illustration of the same mechanic.) Since there is a unique replacement for each of the 26 letters of the alphabet, this creates a cipher whereby the replacement bigram stands in for the original letter. So SU decodes to A, ED decodes to B, etc.
Deciphering the three messages at the bottom gives the following clues:
The final answer to the puzzle is NATIONAL WEATHER SERVICE.