If you report after the Christmas break you will be 30 days in the hole as far as leave goes. Don't think its a good idea. But what do I know, i'm in the same shoes as you are. Delta Co. Rah!
Being 30 days of leave in the hole.... isn't that bad considering you will be in training for 1-2 years. At 2.5 days per month, you should easily get back to around 30 days of leave on the book. To put it in perspective, I have just short of 10 years in the Navy and have taken taken leave 3 times in my career, sold 60 days when I reenlisted to go STA-21, and I am still at 50 days of leave on the book...
My advice, enjoy the time off and especially if you can swing it with family, before you are unable to do anything other than eat, sleep, and breath flight school and your first operational command.