I now think it is very much a long shot to get off the wait list. It turns out there were only 29 ceramics artists accepted into the "retail-only" section of the show. Most of the names I recognize, and all are fabulous! Lots of "oooh!" and no "eeeww!" But numerically, it doesn't make sense that the 29th person on the ceramics wait list will get one of the 29 spots in the show. That's ok. In fact, knowing I got the 58th highest score amongst this class of artists makes me feel pretty good.
ACC has changed some of its policies since I last worked with them in 2008. Back then, in order to reserve your spot on a wait list, you had to pay a deposit. And if you cancelled your commitment later, you forfeited that deposit (this is just one of several policies that made me raise my eyebrows back then). But it's different now, I only need to say "yes" without sending money. And they made it clear that this does not obligate me to say "yes" again if my number comes up. It's like they now understand the crux of my dilemma, that it's hard to prepare for a big show when you are on a wait list.
So I said "yes" to the wait list. But I'm not going to kill myself making inventory for the show. I will work on it if I have time, without pressuring myself. If I get a spot in the show and I have enough inventory for it, there is good potential for long-term gain, by exposing my work to an audience that is mostly new to me. If I don't get a spot in the show, having the extra inventory is not a bad thing, as pointed out by Jonathan and Ray. And if my wait list number comes up, and I don't think I have enough pots, I am comfortable with the idea of saying "no" then. After all, the show will come around again next year, as pointed out by Jim.
Thanks again to everyone who helped me sort this out. I can put this decision behind me, and go back to concentrating on the Bethesda Row Festival, coming up next month.