Short answer: Do it now, before the traffic shows up. Post your holiday hours, test your contact and checkout paths on your phone, put one seasonal offer on your homepage, lighten your heaviest pages, and set up an auto-reply that tells people how to book while you're away.
I build and care for Squarespace sites for small businesses, and November is when the small fixes pay off. Here's the checklist I run on client sites before the holidays.
The Pre-Holiday Checklist
Post your holiday hours. Put them in your announcement bar, on your contact page, and on your Google Business Profile. Same dates in all three places.
Test every path to yes. Fill out your own contact form, book your own consultation, buy your own gift card. Do it on your phone, because most of your visitors will.
Lead with one seasonal offer. A gift card, a holiday package, a January booking window. One clear offer on the homepage beats five buried in the menu.
Lighten the load. Compress oversized photos and trim autoplay video. A slow page during the busiest week of the year is an expensive page. My images and video roundup walks through how.
Click every button. Broken links hide well on a site you look at every day.
Write an out-of-office that sells. Say when you're back, and link to where people can book or buy in the meantime.
What Not to Start in December
A full redesign, a platform switch, a brand-new menu. Big changes need testing time, and the holidays don't have any to spare. Keep a running list of the bigger ideas and give them to January. That's what January is for.
A Little Seasonal Flair (Without the Clutter)
A festive banner photo, a holiday color in the announcement bar, a gift guide post. Leave your logo, fonts, and core palette alone. Your brand should look like itself in a scarf, not a costume.
Want It Handled?
Well Kept, my monthly website care plan, covers updates, speed checks, and seasonal changes like these, so your site is ready before you are.