Mobile Fortress in the Frozen Apocalypse

The weather across the world collapses and an ice apocalypse sets in, with temperatures dropping past what people can live through. Some of those people mutate into zombies that eat flesh. In her first life the narrator survived on 100 tons of coal she won in the raffle at her company's annual party. A colleague who had acted like a friend turned on her, and she was killed. She wakes up again on the day of that same party. This time she picks the RV from the prize list instead of the coal and rebuilds it into a fortress she can drive, and an RV system wakes up inside it. She sets out into the frozen world with new dangers closing in.