Late summer is the sweet spot for a harvest dinner when the weather is still warm and the produce is at its peak. Start scouting your venue and confirming your guest count at least six weeks out to keep your costs under control.
Hosting for the neighborhood doesn't have to break your bank account all at once. By breaking the $500 total into smaller pieces, you can focus on the food and the company instead of the bill.
Remember that the 0% intro window is a deadline, not free money. If you have a balance left over when the 18 months are up, you will start paying interest on whatever remains, which makes everything more expensive.