Yours should have it, and it takes quite a while to freeze the DEF, not a flash cold spell but prolonged cold. The flash came out in 2015 for the 2014 and 2015 trucks.
I been driving the truck for a few days now with cold weather but nothing as cold as when I had the issues. As of right now I believe that the relay was the issue all along.
The flash causes a heater to run more often even when the truck is off. Mine never had an issue and as far as I knew it never had the flash. Now I do not have to worry about it...