What Jason said is exactly correct. If it is cold and snowy you will not get the EPA figures in any car. Hybrid features like auto stop are not going to work until the car is warmed up and some models auto stop will not work at all below a certain temp. Auto stop is only a small fraction of the total number tricks a hybrid uses to get good mileage. The only hybrid feature that would hurt the heating ability is auto stop and auto stop is not gonna be working while the car is cold.

The primary way a hybrid saves gas is by using the electric motor to help the car on take off and also when going up hill. The energy for this extra boost of power comes from when the car is stopping or going downhill. In such cases the motor functions as a generator and puts charge into the batterys for later use.

The big question for you is if the battery will last long enough to climb such a serious hill. If a hill is too long and steep the battery will not be able to help for long enough. I'd ask people making a similar commute that already own hybrids how well they work for job.

My area is hilly but no hill is too much for the my Civic Hybrid on my regular commute. There is a hill in the area that is so steep for so long that it killed the pack but I've only been over that hill one time so I can't really help with this issue. The one time I did go over the big hill I had the cruise set to 70mph in 5th gear. After the battery ran dead I had quite a struggle getting over the hill and ended up only going about 45mph in 4th gear. Had I downshifted sooner the results might have been better but I can't say cause I've only done it the one time. The car took all the other hills on the entire trip in 5th gear and it didn't slow down under 70 miles per hour.

Your hill seems to be big enough to cause a hybrid system some trouble so please check with the locals to see how they do it. While you are at it ask em if they like their hybrid.