PV=nrT
As the Temperature decreases so will the Pressure, given the same Volume. So yes, you may notice a slight decrease in tire Pressure, that will increase (all by itself) when you warm up the gas in the tube.
That being said, I doubt it is enough to matter.
I wish 40-55 was "cold" too!
it is 35 here this morning, so I guess I have to put on some leggings and a long sleeve jersey. I use CO2 on all my rides, and in the winter below zero is not uncommon.
zac