A quick update: we left Monpazier on Thursday morning, and learned the hard way that the GPS in our car has a few glitches. At one point, it showed us traveling across an empty swath of green pixels (which I definitely would have noticed, instead of the highway we were actually on). When it did locate us on an actual road again, it was off by several kilometers from our real location.
Nevertheless, we did make it to Carcassone where we spent the night inside the castle walls. In fact, we got a surprise upgrade from the 3-star hotel we had booked to the 5-star Hotel de la Citė, due to a problem of some sort with our original room. We had a nice (but very windy) dinner at an outdoor cafe overlooking the fortress, then wandered around the ramparts a bit before bed.

Flamingoes!

View from our hotel of the place next door. It’s supposed to be very nice, but I don’t think I could stay there without giggling at the name constantly.
We walked around the old city for a while, found a nice place for dinner, and then hung out in the bustling square in front of our hotel for a drink. Back in our room, we fell asleep to the sounds of younger and hipper people enjoying many drinks of their own in the very same square.
I can’t believe we only have four more nights in France!