Anti-freeze

The changing weather has reminded me that I need to prepare for freezing temperatures.  The RV needs to be emptied of water and the drain traps filled with antifreeze. 
      While we're away from home over the winter I like to do the same for the traps in the house.  I'm not worried about frozen pipes there but the antifreeze won't evaporate and allow sewer gas inside.
     And the hot tub piping will need protection as well.  
     The days are still warm now and nobody is much worried about the cold,  but trying to buy antifreeze a month from now might be a problem.