I had no problems attempting my first HDR Project a couple months back and it was around -20C + wind chill.
I had no problem taking the 5 exposures for the HDR x about 12 or 14 rotational changes for the 180 degree panorama. The camera didn't seem to have any problems, and when I got home I left it in the bag to thaw slowly. I certainly wouldn't feel worried doing the same thing again in the future.
p.s. my 2nd post on the forums, first one adding a image so I hope it doesn't put it as original size in the forums or I might get heckled....
*edit as it indeed adds it original size...
Steven