This year saw four CFLs popping over the holiday period in our house. I have noticed it in the past too, and although I've never bothered to check it out, I suspect the reduced industrial/commercial load over the holidays results in the voltage creeping up to the peak permitted value, which old bulbs don't tolerate well.
I am replacing them with LEDs as they fail, so the failure may save me money, but it remains to be seen how reliable LEDs are. I suspect they will not be any more reliable than the CFLs were.