A good yard game setup turns a standard reunion into an actual event. Booking in the spring is your best move since the pros get booked up fast for summer weekends.
You want to have this sorted well before the family arrives. Spreading the $200 cost over a few months keeps your cash flow steady while you handle the rest of the planning.
The 18-month window is a deadline, not a gift. If you still have a balance once those 18 months are up, the bank will start charging interest on the remaining amount.