If you are buying this now (for a December gift-giving), I'd strongly suggest you open the box now to make sure it is defect-free.
If you do that, then you might as well charge it fully...say a week before the giving.
Explain this all after the unwrapping, of course.
Also, let it get to 50% then store it for the few months. Apple recommends this: Store it half-charged when you store it long term. https://www.apple.com/batteries/maximizing-performance/