I left my D in the care of my parents when I was in the Army in the mid 2000's. It was garaged on car wheel dollies so it could be moved, my dad started it up every now and then, pumped the clutch and brake pedals and that was it. I would put it on the road and drive it if I was visiting them on leave.

In the instance I did not have my parents as an option, I did contact some vendors about long term storage options with them. I wouldn't trust anyone else to take care of it IMHO.