Have winter camped in a Dutchmen, which was not as insulated as the Oasis -more cold air seemed to seep in than in the new Oasis.
We winterize by mid November. We bring a sickroom/bedside commode like this one: MedPro Versatile Homecare Commode Chair with Adjustable Height | Walgreens
to put in the bathroom for toileting (plastic bag, kitty litter style), bring jugs of water and wash up in basins of water that we heat up on the stove.
But, we don't winter camp in bad condiitons, just on the occasional nicer weather weekends in winter that are not snowy/icy. The ten miles from my house to the interstate are not for the faint of heart. I rarely drive my front wheel drive car on winter WV hills. We commute together in the 4wd truck.