I’d say get them listed now 
I’ve had Christmas card and sticker orders coming in over the last week. I usually find Christmas orders start to come in throughout October, and then from the beginning of November it gets really busy. Your listings will last through beyond Christmas at this point, so if you’ve got stock ready it’s worth getting it online now.
Agreed on that timescale. In normal years we are away all September in our motorhone, so I leave a note on my shop front asking people to contact me to reserve. I open my shop the night before we leave France for home and usually have a stack of parcels to post out first day after our return. This year I was only closed first two weeks as we decided to avoid France 
and I’ve been getting busier and busier since my return. The geese are certainly fattening , 