I wouldn't hesitate to pack a long skirt. They are lightweight and take up no room. I'm sure you know not to take one that is too long (to touch the ground) or too narrow of a hem. I'm seeing these long skirts everywhere and I live in a tourist city. I went to a brunch a couple of weeks ago and 2 women at our table were wearing them as well as a lot of other women. If you are unsure about the coolness of the weather just bring some tights to wear underneath.

Thanks for your help elizzie. Going to pack one long skirt and one maxi-dress along with some tights. Weather does look cool at night so think layers are going to be the way to go.
z--thanks for the advice about the packing envelopes...bought some over the weekend and suspect they will be perfect!
Appreciate the help!