Our RE ADR Heavy Plant vehicles on a RAF Station in Germany used to be, fully serviced, If Petrol this was drained, Diesel was filled, the machine bagged up in a very big rubber bag, placed on axle stands, batteries removed, all sharp edges padded, bag sealed and dehumidifier switched on.
These machines were often left untouched for up to 7 years and started again on replacing the batteries with no great difficulty.