They already were, claiming China will pick up the loss (but at a 20-30% discount, and with prices continually falling, Russia will lose money on the deal). Blowing them up permits Russia to attack western infrastructure.
Europe is not going to "Freeze" despite constant propaganda to the contrary. And Russia is set to suffer much worse during the winter than any temporary pain Europe will feel.
How could it possibly freeze? They've been telling us that they are suffering from global warming, making the seas boil, and making eggs fry on asphalt.