It's hard to run a small shop with just 2 employees. Usually, when one of us takes a vacation, the other will continue to get orders out, but this year there was an emergency surgery with a long recovery time.
With a pre-scheduled vacation in early December, this means there's no one to assemble, pack, and ship orders. The products are typically complicated, with many parts, so training someone else at the last minute simply isn't practical.
Sorry, but we don't have a choice: any orders placed between Dec 3rd and 10th will have shipping delayed until the 11th at the earliest.