Oil Coolers& Cold weather q

I'm running a ps fluid cooler and an engine oil cooler. The last couple of nights/mornings it's been in the single digits, so can I over cool the engine or the PS pump or should I not worry about it? I only wonder because the oil& PS coolers are on the jeep are meant to cool it down in HOT weather, ya kno?

From what I've read, too cool of oil is not good. Probably should run arround 180 degrees. I'm currently installing an engine oil cooler in my SBC powered XJ. I'm using Perma-Cool's oil thermostat as discussed here: http://www.perma-cool.com/Catalog/Cat_page14.html