On our first trip, I insisted that we bring some dressy clothes. We wasted valuable gear space!!! Don't do it. You'll find that it's way to warm to wear what most of us call "dressy". You'll both be happier with t-shirts/tanks, shorts & flip flops.
If your honey wants to dress a little, maybe she'll want a sarong & tank top. It's festive & completely in line with local dress.
After two trips and our third planned for thanksgiving I've almost got it down!