I can't speak to whether or not you can do it, but personally I don't like to set goals like that -- it just makes me more desperate and I don't like the feeling. Plus, I can't control the
Instead, set behavioral goals to accomplish between now and then. 12 weeks is a great timetable! (but please tell me there are more than 12 weeks between now and Dec 18th! Our 10 week term that ends before thanksgiving hasn't even started yet!!
Step 1 might be to identify the parts of your plan that need the most attention (e.g., eating, exercise) and address the most important ones. Set goals for how many days you'll exercise, or something like that. Make the goals behaviors you can control, rather than the
scale, which is evil and fickle.
The NICE thing about a 12 week (or other short term) goal is that you can make a lot of progress -- even if you don't lose all the weight, getting things set in motion and working for toward goals is a great accomplishment. Maybe you can say that you exercised XX of the YY days! Also, getting yourself in gear may make you less likely to really go off plan during the holidays.
Of course, you already know about great accomplishments, having lost 110 pounds so far!