Iceland in April and May gives you the best of both seasons. The heavy winter crowds are gone, daylight stretches late into the evening, and car rentals are cheaper before the summer rush. You get waterfalls, black sand beaches, and wide-open Ring Road views without peak-season prices.
A solid week-long trip for two lands around $3,900 once you cover flights, vehicle rental, fuel, and meals. Instead of draining your savings all at once, you can spread that cost across a repayment window without running up interest charges.
Keep in mind that a 0% intro period is a strict deadline, not free money. If you still have a balance when the 18 months wrap up, standard interest rates kick in on whatever remains, so set up automatic monthly payments of $216.67 right away.