I have to agree with Wayne, that in general, the Hybrid will take a bigger hit % wise in winter... but maybe not much more. The reason being?

In winter a hybrid car's gas engine is less efficient, but then again, so is a non-hybrid's gas engine.

However,
In winter, a Hybrid's battery is less efficient also.
A non-hybrid car has no such battery pack to be affected.

Thus, a hybrid has two strikes against it, vs. one for a regular car.

You're still going to be saving gas though, regardless... that's the good news!

( as always, your results may varry..... )