I am very curious what interesting things you have prepared for us with Christmas approaching. But I can already tell you that I would find it very interesting if you made something like an advent calendar event for players, similar to what World of Tanks has (for inspiration). Players would know in advance what to expect on which day and prepare themselves for interesting rewards. I'm not saying you have to do it the same way as that game, but if you were smart enough, you could figure out how to make an interesting advent event for us.