I do not winterize and I often go snow skiing and boondock in the parking lot of the Ski Resort. I have survived 17 below zero without freezing. But it takes planning, thinking ahead, and some small modifications. My first motorhome was really good at handling the cold, my latest was very poorly planned and froze up easily. I had to do some re-plumbing to move the water lines up out of a bottom compartment and add a bunch of insulation along with a thermo operated recepticle to operate a heater for really cold (around zero) weather or just a 100w. light bulb for milder freezing weather.
I also have a EC30W automatic Generator starter so I don't have to run my generator 24/7. Keep in mind that there is alot of plastic, (hoses, fittings, etc.) on your motorhome and in freezing weather they break easily.
Plan ahead on when you will need Propane, keep fuel topped off, and plan on where and when you can dump and fill your fresh water tanks. You cannot remain hooked up to outside water as the hose will freeze so plan on running off your tanks. And keep in mind that the dump fittings will freeze, I put some pink antifreeze in my tanks when i dump to keep them from freezing.
Also check your route and find RV parks that are open where you will be wanting to stop.
Good luck, drive safe, and plan ahead.
An RV'r is someone driving a $300,000.00 Motorhome towing a $40,000.00 car and looking for a free place to park.