That does help immensely, kp.

I have seen a wedding dress after it has been worn and walked thru the streets of Italy. You will have to have it dry cleaned. Look now for a professional dress cleaner that specializes in high end items such as wedding gowns.

Please consider my idea of a vacuum packed bag that you can shrink down to an accetable size for carry-on. I travel with these bags all the time and they are a treasure.

I see no reason why a dress of this size and style could not be in a carry-on during your trip home. You will not be concerned with keep it wrinkle free as you would on the flight over. I took care of this for my friend on both the flight over and the way home. (The way home was much less stress, lol) You should be able to shrink pack it and keep it safe under the seat in from of you or in an overhead bin. (And save $350 to boot).

Have fun - weddings in Italy have such an enchantment about them.

Thanks everyone for the good advice. I think I'll bring both a carry on and checked bag--with packing materials and a space saver bag in the checked bag. That way I'll be prepared for anything.
I usuallly travel with only one bag--but this is a special trip.

We were married in Santorini. I carried it on with me from the states to London where we stopped-over for several days and then onto Athens, Santorini, Athens and back to the states. The flight attendants on each airline / flight were happy to hang it for me as soon as I stepped on the plane(s). If you are worried about lost luggage, I would just carry it and they should hang it for you. :)