Are there any best practices for non-use of your Model S, particularly around the battery? For example, if I'm away on business and will not be using my Model S for a long period of time, what would you recommend if I'm: 1) Away for 7-10 days? (Leave the car plugged in the whole time in my garage?) 2) Away for 11-20 days? 3) Away for 1 month? (Have a friend take it for a drive while I'm away?) 4) Away for 2 months? Thanks for any tips.