3-4 month hibernation for s8

[denkas8]

greetings.
i have to travel abroad for 3-4 months due to work purposes, which means leaving my s8 in the garage.
would it be worth the effort to ask a friend to start it up and let the motor run every week, or should i just unplug the battery until i am back?
the car is insured for myself only, so my friend can only start it, but not drive it around.
regards