You sorta answered your own question by talking about where you live. Heck people leave the north to go spend their winters in their trailers where you are. If you live up in the frozen tundra where we are...we packed it in almost a month and a half ago. It is totally dependent on where you live. In your area you are probably ok to just blow lines out...but, and it always comes down to but......last year you guys had an unusual cold winter, same could happen again this yr. If you just blow the lines and store it, and you get to enjoy the Polar Vortex like the rest of us, it will be too late if damage is done. So...why not invest in $10 of antifreeze and do a full blown winterization. The added benefit is your seals in the plumbing remain lubricated from the RV antifreeze and won't dry out. It's cheap insurance.
2011 GMC Sierra 2500HD
2014 Rockwood 8289WS, Diamond Pkg.