Frozen parking brakes

[ClayJ]

Every time the weather dips really low, I notice that my parking brake seems to stick on. I pull the release handle and normally there is a louth THUNK as the pedal pops up and hits the roll bar. But when its cold it only comes up a little bit.

If I let the engine run for 5 minutes and warm up it seems to melt whatever is frozen and the pedal slowly comes up. (I have dual exhaust).

Do I have water in a line somewhere? What steps should I take to resolve this?