I would leave it plugged in with the charge threshold set at 50% as others have said.
In addition, make sure that you can access the car from a phone app, Visible Tesla, etc to verify that charging is still happening. With the App and notifications on, you will see that the Vampire is being fed every few days which is a good reassurance that all is well. If for some reason the charging stops, then the Vampire will drain the battery. If you can leave a key and access with someone there, they can restart charging (unplug and replug is usually all that is needed) or take other measures to get charging started again.
To minimize the Vampire drain, in Settings, under "Display", turn "energy savings" on, and uncheck "always connected."