http://www.smartcockpit.com/pdf/plan.../systems/0019/
Scoll down to nearly the bottom of the fuel page for the 737NG.
It says "Minimum inflight fuel tank temperature: 3°C above the freezing point of the fuel being used or -43°C whichever is higher."
I have seen this limitation on other aircraft.
As a side note, I believe that aircraft that use fuel icing inhibitors are typically ones that don't have oil to fuel heat exchange systems such as some bizjets.