Baby shower date issue

I had set the date to our baby shower a while back and asked my family if there was any issues with the date, asked my husband if his side of the family agreed as well. Everything checked out and i had the invitations printed. Turns out his sister has a camping trip that weekend (paid for and can't cancel, my hubby forgot). I suggested to my husband to put a sticker over the date and write in a different one. He doesn't feel the need to change anything. It's our third and mostly just wanted to celebrate baby and get family and friends together. What would you do?