IAD sales are Saturday and Sunday. You can try to arrange sales in advance with vendors who are willing to do so - but I think you'll find a fair number of frogs on the show floor.
Flying with frogs requires a little advance planning of how you will transport them to keep their temps and humidy stable and to keep them from being jostled. I have flows from the West coast to the East coast with frogs. I didn't advertise that I had them and had no problems (ran them right through the xray in a small backpack).