A deferral letter is neither a rejection nor acceptance. Take a look at the glass half full and think of it as a second chance to impress the admissions committee. A student is deferred when there isn’t enough information or context to put them through a full acceptance.
Engaging in a hobby that is important to you can be a great way to be productive on vacation. Take on extra work shifts or apply for part-time jobs over the holidays, but don’t ignore rest, recharging, and recuperating.