The culprit is right here in your post...short commute, cold weather and hills. A block heater would help but with a 2.5 mile commute it may not do much . Your car is probably barely, if not at all, getting up to operating temp. I would suggest taking a couple of longer trips during the week or on the weekends. That will give the car time to warm up and you can practice getting it into EV mode. Another suggestion is while driving to work let it coast as much as possible (take your foot off the gas) especially going down hill. Accelerate up the hill and just before you reach the top of the hill slowly let your foot off the gas and let the momentum carry you up to the top and let it coast down the other side...You may even try to feather the gas while coasting downhill so you can pick up speed and allow the momentum to carry you as far up the next hill as possible. Obviously you want to impede traffic as little as possible but it can be done. As mentioned above you do have to learn to drive the car to maximize your mileage. There are many good posts in this forum to improve mileage. Spend a day reading and take a trip and try them out. Good luck and don't be afraid to ask questions.