I suggest a 7 day cruise on any of the major or premium cruise lines and you and your family will have a great time. The only drawback to a Christmas cruise is that you will pay a premium, that is, top dollar. And you must make your reservations far in advance. My children (ages 11 and 6 when we went on a cruise to Mexico) loved the sense of freedom that they had on the ship. You will love the freedom from cooking, shopping, cleaning, and fighting traffic from one soccer game to piano lessons AND your employer! And your husband will be free from nagging, home repairs, his friends, and his mother in law.
As you proceed in your cruise planning let us know if you need help. There is a fair amount of planning that needs to be done, but this board has lots of very experienced cruisers who will gladly help you.