As far as waiting? IDK. You could get them now as they might run out by January. I think Neal got 500 “sets” of them which should be plenty, but you never know.
It seems this special price on 35E cells is only for those who are buying the GT at the present moment. If you are in the 555 to 1000 group you have to wait until you order the light to pay for the batteries. You can still sign up for the cells now, though.
I got my cells (30Q) over a month ago. They just sit here waiting. Lol