You don't mention how it's going to be decorated so if you need to make any of the decorations now is the time. Just remember some colors fade so you'll want to petal dust (if appropriate) and store in a dry dark space. Also, all the details - cake boards, ribbon, non-skid, stands, dowels-SPS. Have it all thought out and ready to go so you have everything on hand and don't need to run out to the store. Have a great vacation!