OK, Time to resurrect this thread--

I'm going to mix up a batch of this this weekend using IDY, will cold ferment until the following weekend (seven days). I'd like to make a second batch using my Tartine starter, which is fed twice a day, so very active. Any thoughts on how much starter to use for a seven day cold ferment? Also will be using Wheat Montana AP flour from WalMart, works very well in the Tartine bread.
Actually, the above question is a bit vague, I realize...I guess I'm asking for a ratio of IDY to starter in general, as I haven't given, or decided on, the number/size of pizzas to make.
Thanks, Bob