I would call a whole team for this one!
Everyone who participated in Hufflepuff's Sleigh Ride this last December were doing their very best to help find the missing students from a portrait. So I know we have practice and I'm sure it would go faster if we all helped each other like we did there.
You wake up at 3am in the night in a cold sweat because you realise you volunteered to decorate the entire great hall for the end of year feast, but you haven't even started looking for the banner etc, much less carry them to the hall or even decided on a theme (when it's revealed who won the housecup all the decorations will just turn into the colour of that house) but you still have to sort out the decorations and you know you won't make it on your own.
Who do you ask for help (and who do you think won't bite your head off for waking them at this time)?