* The prize varies: Morrisons' prize offers change frequently. Sometimes they might offer a trip to Disneyland Paris as a prize, other times they might offer something else entirely.
* No public data: Morrisons doesn't publicly share the number of people who win their competitions or how many of those winners choose to go to Disneyland Paris.
* Many factors influence choice: Even if the prize is a trip to Disneyland Paris, there are many reasons why someone might not go. They could have other commitments, not be able to travel, or simply prefer a different destination.
It's impossible to give a specific number without more information.