I just want to say sorry for everything you're going through. I understand that feeling of pretending to be a family because I haven't told my family what's happening and asked my husband to make an appearance when meeting up with my brother who was in town this week.
If your wife is freaking out then maybe she should consider working on the marriage instead of working towards divorce! It's too bad this is how Christmas has to be this year. I hope it will make her have true second thoughts. I also hope you'll still enjoy the time with your kids.