Carcassonne: day trip or worth an overnighter?

You might want to read through this recent thread.
https://community.ricksteves.com/travel-forum/trip-reports/what-s-wrong-with-carcassonne

Like many of the small but popular towns in Europe, there is value in being there in the very early or late hours - something you can't do on a day trip.

If you're gonna do it, probably best to do an overnight. Because during the day, it's mobbed. Do it as a day trip and you see it at its worst. Be there early (very early) and late, and you can still enjoy its magic. The same is true for anyplace in Europe that's become too popular (Mont St Michel, Toledo, Cinque Terre, et all). Woe to anyone who just shows up for a few hours mid-day.

You should read this post just added a few days ago (it's in the Trip Report section):
What's wrong with Carcassonne?

Hi Eugene, if you’re a photographer, plan to stay overnight. We got some excellent photos after dark, after the crowds left. The castle is beautifully lit and you’ll have the place to yourself. Very cool.

Hi Eugene. As others suggest have a read of my post on Trip Report.
It probably comes down to what YOU enjoy and what YOU want from your travels.
Most posts I read on this forum indicate the posters want to see the key sights and do so as quickly and efficiently as possible.
That is fine and if that is how you want to do things then maybe hit Carc late. Check out the Cite late afternoon early evening after much of the crowd has left.
Get up there early the next day and maybe do the ramparts/Comtal tour then move on.

My wife and I are different cats. We travel in a different manner to most of the posters on here. As I posted on the trip report we actually enjoyed Carcassonne not just the Cite.

Yes, overnight so you can walk the ramparts at night. A very memorable experience!

We arrived there late afternoon and stayed overnight on our way to Toulouse to fly home. By the time we arrived, the crowds were gone. We stayed at a Best Western inside the walls (I remember because I try to avoid chain hotels on vacation). It was nothing special but adequate.

I visited 48 years ago and recently read my journal of the visit. I wrote how much more I enjoyed it early in the mornng before the crowds arrived !

We stayed initially at the Astoria. Near the station, pleasant, clean, comfortable, cheap, decent brekkie, helpful staff. Moved on to a place called Art House B&B. Very nice. A little pricier but still great value.
As I have said in my trip report. The town, "the Bastide" is a delight. There is more than just the Cite.

I camped walking distance from the Cite. I day tripped away from Carcassonne but enjoyed walking through at night.