That moment the night before the wedding is about relaxing before the main event. You want the food and drinks to feel right without the stress of an immediate, massive bill.
Since you are booking a year out, you have time to map this cost before the big day arrives. Use this lead time to treat the bill like a monthly subscription rather than a single punch to your savings.
Remember that the 0% intro window is a deadline, not free money. If you have a balance left when the 18 months expire, the bank will start charging you standard interest on whatever is remaining.