To be honest, if your husband's application is not extremely complicated there's a pretty decent chance it will be decided before Christmas anyway.
If I were in your situation, I would submit the application normally and then wait. If his visa is decided before Christmas then that's great, if it's not - make sure you notify the case officer that you are planning on leaving the country during x and y dates.
Notifying the CO is the number 1 thing you must do. However when first submitting the application, you won't have a CO immediately. It's very likely that you'll be assigned one in less than 6 months though.
I'm no expert and my advice above is just based on what I've read and seen around the forum.