You should check the various
You should check the various car model parts of this forum for specifics about each model. My impression is that the Prius may have some problems in slipery snow but the rest of the hybrids do just fine in cold temperatures and in snow. Of course, your mpg won't be as great when its cold but it will still be a lot better than a non-hybrid in the same circumstances. The batteries may not give you quite as much boost when cold than in warm weather but the cars will still work ok. Engine block heaters may be helpful with hybrids when it is really cold, just like with any non-hybrid. The Ford Escape Hybrid 4WD has been noted to be quite good in snow.