I've had great luck in emailing (or calling) the catalog from which I ordered trees, etc. and asking them for help. If you purchased it locally, they too should be able to help. They usually email back quickly with specific instructions. Also, in most cases, they will replace it if it cannot be saved. Is there a possibility you could go ahead and transplant it but keep it safely covered until your weather warms up? Generally, sufficient light and water would be the first thing I'd check. Also, is it possible that olive trees lose their leaves each year at this time, like fruit trees do?

olives are evergreen they can't lose all the leaves at one time...... i have 2 arbequina's planted in my backyard........ they are both doing great!!!!!!! 2nd year and i have a couple of olives on each tree..... hopefully next year will be a better year....