Hmm … 😄 I took a very similarly shaped, voluminous cotton dress to the south of France a while ago, and felt remarkably dowdy and wrong in it. (Which almost never happens!)
It may be that the inclusion of silk makes this one airier. It may be that you don’t turn into a puddle of sweat in punishingly hot weather. There were other women who wore voluminous plain cotton dresses and didn’t suffer. But if you have the slightest doubt, imagine how it might look and feel when moderately damp. And heavy.
(I recall on that trip how I envied the French women arriving day after day to our event in tiny white vests and little suede mini skirts. Or those in incredibly light strappy sundresses with little crocheted cardigans.)
Maybe take it but have a back-up, in case it doesn’t seem perfect when you arrive?