I'd wear hose if I felt it was appropriate for the event but it also depends on the outfit you're wearing. Sometimes bare legs are fine depending on your age and the age of the people you'll be with. I think most women are currently wearing the textured/patterned hosiery or colored, opaque tights rather than the plain sheers but that may be more for the younger population. I'm not much of a fashionista so I tend to wear what I feel comfortable in even if it may not be on the cutting edge of current trends. The gown you described sounds as though you could go bare legged and maybe use a wrap around your shoulders as the previous post suggested. That way you won't feel over-exposed.
I would wear what you're comfortable with that way you can be natural and not feel self conscious about what's on your legs. If you feel good about what you're wearing, you'll be more confident at the party. I hope this helps! =)