I'm an advocate of running it for 10-20 minutes every two weeks or so.

Cycle the AC.

Your batteries lose charge just sitting there..and this is worse in cold
weather.  The surest way to shorten battery life is to allow sulphation to
occur at reduced charge.  Therefore, keeping them fully charged with either
an electronic trickle charger, or 15 watt(ish) solar panel with charge
controller is the best thing you can do for the batteries.  Check
electrolyte level if applicable.  Reduced charge can also lead to
freezing.  So on the battery side, there is no need to remove the battery,
disconnect it, or keep it warm.  Just keep it charged.

If you don't use the emergency brake, don't engage it.

Brake fluid is almost always overlooked.  It should be flushed every two
years...winter storage is a good time to do it.