I dunno. It wasn't that cold here in Hertfordshire yesterday morning. Sure, there was a little frost on the car, but it was hardly frozen solid, certainly not enough to call it a cold snap. It was only down at about -1 to 0degC. For it to be a real cold snap it needs to get down below freezing for several days on the in a row and ice on puddles won't melt at midday. After all, it is mid November, it is meant to start being cold!
A good frost really sets back the following year's bug population...roll on the cold!