Rishi,
Don't stress too much about exam preparation. If you've done the SAC and are moving on in class then just go with the flow. BUT if retention is an issue, then maybe some summary notes would do you good. My recommendation is to have two different quote repositories: one ordered by characters (eg. one for Scrooge, one for Tiny Tim etc. Can be quotes from them or about them, or both) and then another for themes (eg. greed, kindness, charity etc.)
Once you're familiar with the text it's just a matter of dealing with prompt types. I don't know who's in charge of the Christmas Carol prompts at the end of the year, but they LOVE their Views and Values questions (eg. 'Dickens presents a negative critique of Victorian society' or 'The audience never truly dislike Scrooge.') Find what you're comfortable with (out of character, thematic, quote, structural, and V&V themes) practice a few of them, and then move on to the difficult ones. Hopefully by the time the exam comes you'll be prepared for whatever they throw at you
Like I said though, focus on what you're doing in class for the moment. These holidays will be good for revising and collating notes, but ultimately there's a reason schools do things in a certain order at certain times, and the other two tasks will require just as much dedication, so be sure to pace yourself