skunkworks

I'm interested in purchasing a 6spd rwd is250. I live in toronto but travel to snowy montreal alot. How is the purformance of the IS in winter. Do all the electronic aids make a big difference or should I just go with the awd varient. The cost difference is quite big so I'm leaning towards the rwd. Of course i would be using good winter tires regardless of which car I buy. Any feedback from owners is very appreciated. Les