if you really want to keep it and have no option other than long term storage I would do like Kaus said then be sure it has a full tank a new battery and make sure the onstar/wifi is paid up then make it a habit to autostart it (via the app) every 3 weeks for the 10 minute timer. After 4 years that would work out to 12 hours of run time probably almost exactly what you would get if you just idled a tank of fuel out. just a thought if it were me and had no other option.
I'm not sure on other vehicles, but on our 2019 Tahoe, you can only remote start it twice and then you have to start it in the vehicle.
Clean the vehicle inside and out to include the under carriage.
Put a good coat of wax on the vehicle.
Buy the best car cover you can afford.
Fill the gas tank completely full and add stabilizer. An empty or low gas tank will lead to internal rust as condensation and moisture builds within the tank. Also add fuel stabilizer or corrosion inhibitors and then drive the car around a bit in order to distribute the additive to engine parts.
Change the oil and filter. Old contaminated oil will cause pitting on bearings.
Flush and fill the radiator.
Check tire inflation.
Disconnect the battery - you're probably going to need to buy a new one regardless when you get back. If you storage lot has electrical hook ups and the battery you have is sealed then a high quality battery maintainer would be nice.
You can pull the spark plugs and spray in some fogging oil.