Bernard,
With the relatively simple air brake system on the Explorer, without numerous valves and relays, as Loggy describes, on modern lorries, you might well get away with it, what you have to be aware of, is that you will not have an auto drain valve ( unless you have fitted one) on the vehicle, so it is quite important to drain the tanks of moisture, that way, with the small amount of use that you would do in the winter, it should be alright.