My sis and her hubby did it a few years ago. They had some sort of package deal (not a tour group) that included lodging, car rental, snowmobile self-guided tours, and tours on the Snowcat thing. They loved it, and had a blast.
The snowmobile company rented gear to them, and someone sent them a list of other recommended clothing. Things like a balaclava, layered outerwear, insulated boots, etc. That would be something to research before you go.
Single empty-nester in Middle TN, sometimes with a friend or grandchild on board