Im going to dp's big huge family party (where i know no one but dp's immediate family) in a few weeks and will be wearing this dress
tablet.hm.com/gb/product/18958?article=18958-B
Not very festive i know 
I absolutely love the dress and for me its very versatile as can be worn casually too. But im one of those people who is always cold! I need a jacket / cardi to go with it in case the host's house is a bit drafty. Also if i go out to the pub i dont want to have to put my big winter coat on over (as i'll never take it off despite looking ridiculous!)