Cleaning viruses and malware off computers.
Snow shoveling, but get a snow scoop. Get a roof rake, and you can do roofs as well...snow loading is serious business with that kind of snowfall.
I'd consider downgrading the car while in grad school. You want something that won't leave you stranded in the middle of nowhere (and no cell towers), but you will save a LOT faster without a car payment.
A rural area has more opportunities for acquiring and practicing rural how-to skills: picking and preserving wild fruits and berries and nuts, hunting, fishing. Sometimes there are creative housing options (trailers, cabins, shacks), but remember you'll need to be near a road that gets plowed in the winter, and always ask: "Is heat included in the rent?"