My car stands in the drive in the north east of England for 3 months over winter ever year as we go to Australia. I do nothing to it before we leave except leave the hand brake off. It's an auto-box so I leave it in Park. It's seven years old and on the original battery, starts first time on return.
I do expect it to fail to start and the battery will give out one day. It gets covered in snow and a neighbough delights in emailing me pictures of it!