Rental cars typically do not come equipped with snow tires—even in snowy areas. They generally have all-season tires, although there may be limited exceptions for Enterprise in certain northern areas that we’ve seen.
If you’re concerned about driving in snow, then your best bet would probably be to rent a an AWD/4WD vehicle which would typically mean an SUV, Jeep, or pickup truck, although keep in mind that many vehicles in the aforementioned classes are 2WD so you’d need to do your homework. Note that all Jeep Wranglers are 4WD.