I reckon I would do a LOT better on 4 spacesavers, no kidding.
Anyway I've done a bit of research and realised the R040 Bridgestones run much too cool for cold conditions. That explains why it's poor in the wet too.
Martin W confirmed this too.
Winter tyres are not just for snow, they are a different compound and suit colder weather so it's not just a tread pattern issue. To be honest I've found that in the 240 on a wet track. I thought my Yoko A048s were too slik so I put my Pirelli road tyres (with lots of tread) on for a session - it was useless.