First, the Sunseekers have enclosed undersides and heat ducts located at critical points like the water pump and dump valves. So running the furnace provides heat to the water system. Second, the Arctic package is a heat pad attached to the bottom of each of the tanks (fresh, black, and gray) . This keeps the water in the tanks from freezing. So you are good to go for winter camping.
Both the furnace and the heat pads use battery power pretty quickly, so if you are not at a site with shore power, be prepared to run the generator some for recharging. Also note that running the furnace is key to circulating warm air underneath to the plumbing. Some people use space heaters instead of the furnace. This will not get the warm air where needed on the plumbing. If you are at a site with water hookups, the water hose is vulnerable to freezing. Use a heat tape on it like they sell for home water lines. Camping World now has a water hose with built in heat tape around it. Or fill the tank, disconnect and drain the hose and let the arctic package do its thing.
2012 Forest River Sunseeker 2300 Chevy