Please, forget 'sexy' when outside in cold weather.  Who cares?  You are OUTSIDE!  If you keep  yourself nice &amp; warm when you are outside then you'll be able to be 'sexy' when you go inside.  Do you want to be sitting inside trying to mend frostbitten fingers, toes, ears, &amp; whatever else might be subject to frostbite?  I don't think so.  In very cold weather be careful about wearing earrings, those metal posts are great conductors of cold.  Along with the scarves (I don't care for hoods, they block your vision) you might want to consider a pair of ear warmers.  They are similiar to ear muffs, but don't go over the top of your head, they go around the back; they are very thin &amp; work great under a scarf.
Those boots are really nice.  I've never seen Uggs that are that good looking.  And, yes, you'll need plenty of warm (not necessarily cute) socks.
Now, enjoy your trip!