Hi Tim -

It seems to be a general problem as the outside temps rise and the aux. HV battery A/C has to do overtime.
This has been discussed in the thread 'HV Battery Cooling' here.

The one solution I have come up with is when below 40 put it in 'N' and brake. This will generally shut the ICE down. Read the post from GaryG there - he breaks it down pretty good and also comes up with the same solution.