We screwed up. Ceremony starts at 6:00 PM. Now that we know, we'll actually be there for our own ceremony!
Sleep somewhere that fits your needs whether we prefer it or not. You can check the "Travel" tab for the link to the Hyatt hotel block and Airbnb info as a starting point.
Tempted to say "something nice" and end it there, but we acknowledge that that's not helpful. "Semiformal" and "Festive Attire" are dress code categories that exist (according to Google). You could try that. We recommend against "Beach Formal," as this party is in the winter, but you do you. Wear something that makes you feel classy and a little bit fancy, but not stuck up or uncomfortable. If all else fails, wear what you wore to the last wedding you attended as a guest.