Can you hear the water pump and find the general location? The water tank is likely under the kitchen counter and there might be a panel secured with velcro that pulls off.
Lazy Daze are made in southern CA and aren't built at the factory with water heater bypass valves or anything much for winterizing. A previous owner could have added something. If not, your choices are to add something yourself, pour antifreeze in the water tank, or blow out the lines with compressed air (using the city water inlet). I added a antifreeze pickup near the water pump and water heater bypass valves on mine.
Hope that helps-