Appreciate reading all the responses. The following text was taken directly from 2015 Jay Flight Owners manual which I found online this afternoon.
It clearly mentions blowing out the lines using air compressor (the other method of course is using RV anti-freeze) which seems much more practical for folks in climates who will continue to use their RV throughout the winter months.
There are two methods of winterizing your trailer based upon your model. Please read, understand and follow all instructions before beginning.
Air Pressure
This method will utilize an air hose to blow excess water from the water lines.
1. Make sure all holding tanks are empty and drain valves OPEN.
2. Run the water pump until it is dry, this will take approximately 15-20 seconds.
3. OPEN all faucets and drains, and the toilet.
4. Using an air hose and adapter (customer supplied), blow air through the city water connection. Any remaining water will blow out in five to ten minutes.
5. Pour one cup of non-toxic RV antifreeze into all drain P-traps.