Looks like the drop rates for Gingerbread people have been adjusted too low. In the past two years I have had only ONE drop with dozens of runs of the mission. So I'm done.
I only need two to complete my collection, and since they aren't combat pets or anything, I'd like to propose putting them on the Vendor to purchase with Winter currencies. That way I can still grind for them, but get the ones I want (or any at all for that matter. lol!)