Booked a romantic weekend. On July 12th.

Title says it all really. It’s my husband’s 40th and I’ve booked flights (non refundable) and hotel (The Merchant, been saving up for a year) on the weekend of July 12th. Which, as I understand, can be a tad busy!! We’re going to Giant’s Causeway on the Saturday but will Sunday be bonkers too? I know nothing about what the weekend might be like. Tips? Thank you!!