Well, if you think its a good idea, go for it. But for a christmas story its perhaps too late for this year - not long, and the chocolate Santas appear in the supermarkets.
I know you sure dont need advice from me, but I've been always thinking that you may be better off writing the stuff you really want to write, regardless of what you think might sell best or what people want to read.
I guess thats how artists do it. I doubt that Tolstoy thought "Lets write a terribly complicated drama and misery story thats 800 pages long, sure everybody wants to buy that!", before he wrote War and Peace.