Review your insurance and make sure it is adequate. If you are in the UK, you need to inform your insurance company as a regular household policy does not allow you to leave the policy vacant for so long.
If there is a chance of cold weather you need to consider damp and frozen pipes. Turning the heating off altogether is not a good plan if there is a chance of pipes freezing. A family friend went away for 8 weeks on a holiday of a lifetime over winter, leaving the house under supervision of a friend. She left the heating on with the thermostat set low so the house should not freeze- but despite those precautions, something went wrong. The friend didnt visit for a while, the pipes froze and burst and the house was wrecked, ceilings came down due to the leaks, it was uninhabitable for months. It cost them a fortune as they were uninsured due to not having advised the insurance company of their absence.
Also do you have a garden with a lawn? You might need to engage someone to mow the lawn if you will be away in warmer months, but they would need access to a power supply and you may need to give access to a shed with your lawnmower in, if they don't bring their own gear (check with them). There is no point having lights coming on and off at regular times if there is a foot of grass and weeds where you normally have an immaculate lawn.
I would also say, don't turn the fridge freezer off completely. Entirely empty it, and clean it, but it will stink if you turn it off, no matter how well you clean it.
It is also a good idea to give someone trusted a key and ask them to visit the property ideally every few weeks. You should instruct them to air the property. You should also ask them run the taps for a good long period of time in ALL the sinks and baths, and flush the loos. This is because of a tiny risk of legionnaires, and also because the water in the loo can evaporate which will cause the bathrooms to stink. This person could also deal with your mail. Try and review all your bills and switch as much as possible to online. Put up a notice on the door that says "no junk mail, advertisements or newspapers please". If possible, set up a mail redirect to a trusted UK address for a few months eg to your parents or a good friend.
Personally I might be inclined to move any very valuable items or personal documents to a safer place - eg in my case, my parents or if that isnt possible, a bank safety deposit box.