Walking into a private club for a surprise birthday dinner with everything handled is a great feeling. You want the room right, the menu locked in, and the bill managed without a scramble.
Because prime weekend slots fill up fast, you need to book at least six months out. Lead-time is your real lever here so you can lock in dates and spread out the costs.
Remember that the 18-month window is a hard deadline, not free money. If you still have a balance left when that period ends, you will start paying interest on what is left over.