It has recently got VERY cold up here in Canada -28oC.  The other day,
when I started my car, the radio had no sound.  The LCD display was
working but very sluggish.  I could change channels but could get no
sound.  After the car warmed up a bit, the sound came on. The interior
temperature wasn't as cold as outside but it certainly wasn't 'warm'.
It only seems to do this if it gets VERY cold and there is no problem
when the car is in an unheated attached garage.

Any ideas?  The car is a 2005 Maxima SE with Bose components.