It will be a very festive atmosphere with the ship all decorated for the holiday season with wreaths, Christmas trees, flowers, ornaments, etc. We've been on about 5 Christmas cruises and will be on again this year, but have never been on a NY's cruise, so can't help you there.
Yes, there will be a lot of families on board but the kids are kept busy with Club HAL and are asked to only use the pool under the dome, so that the adults can enjoy some peace and quiet at the aft pool.
There will be a Carol sing Christmas Eve with a number of the Officers and crew particpating and Santa arrives Christmas morning for the children - each get a present.
It's a happy time for everyone and I hope you will enjoy yourselves.
What ship are you going on?