So it happened again...
I rode this morning and it was 21F plus wind chill. I noticed about mid point (in my 10.5 mile one way ride) that rear brake was not releasing. I could feel the drag. This is the second time that it has slowed me down. Last time it completely stopped the rear wheel and would not release at all.
So not only was I fighting headwinds my brake was slowing me down. 
I am not sure what I need to do about the brakes. 2018 Salsa Journeyman 650b with mechanical disk brakes. Why would the brakes stay applied? The lever is in the right position (as if it was released) I will post another
thread about this issue.