Ideal temp for retarding final rise of sourdough

Hello!

I operate a small bakery that supplies several restaurants/bars with bread. I typically retard the final rise overnight in a commercial refrigerator that sits around 40-41F. However, said unit kicked it yesterday. As a temporary solution I do have a wine cooler that sits at 50-51F. I am hoping to use the wine cooler (so that I don't have to cart all of this shaped dough home with me), but fear I will compromise my product.

So, my question is: What is the ideal temperature to retard the final rise overnight? Are any of you able to predict what changes I might anticipate? I am located in Toronto, if that helps.

Thank you for your help!

lahm