Until just recently, BLT theme park view never had an 11 month issue for booking. Then, on Jan 3, 2017, the studio (and resulting 2BR lock-off) disappeared right at 8 a.m. for Dec 1 through 3, 2017, marking the first time Theme Park view ever became an 11 month issue. Dec 4 disappeared right at 8 a.m. on Jan 4. Then this morning at 8 a.m., Jan 5, the theme park studio went down for both Dec 5 and 6, meaning those with a Dec 6 start date, who will be going on line tomorrow to book a theme park studio right at 8 a.m., will find they have already lost the race.
Whether it will also have an issue Christmas week is now an unknown but I believe you will probably be OK including because you state you want a week that begins "a few days" before Christmas, meaning Dec 22. If the 11-month issue is going to exist for that week, it is not likely to begin before Christmas (and is more likely to be an issue, if at all, nearer NYE). In fact, if I were going to suggest a beginning walk date for Christmas, it would likely be Dec 21 or Dec 22.