wider wheels/tyres will more than likely give you less grip in very cold, wet, snowy conditions.
True I see where your coming from. But im looking at it also for a longer term, as these wheels i have now spin up for fun when it rains in summer so most of the summer time i cant put all the power down. I personally think its the tyres too, but the more rubber the better in the summer.
Ill take a look at putting winter tyres on mine for the winter months and swap them over in the summer to a wider set. Do you know what other makes and model cars have a simular offset to the polos or is it just going to be a case of trauling the net to see what there is.
Cheers for the help
Gav