Can only speak as I find. The last 2 years, in Feb and March I (along with others) have been told to go. Of course somebody arriving a couple of weeks later may be left alone,and be non the wiser.
Virtually every wild camp spot in Spain changes in accessability from year to year, just depends on who's complained to the Police, and whether they, the Police that is, have anything better to do that day.
This is why it pays to have plan B, personally I don't like to get to a spot only to find that everybody has just been evicted and I have no alternative site on hand especially at night.
Of course the best info on wild camp spots is obtained networking whilst travelling you can't rely too much as I've said on last seasons information.