Since tomorrow is the biggest party of the year ...

Your friends really suck. A true friend would find you a companion for the evening. They don't cost much.
This situation requires serious strategy, and some skill, but works equally well for both men and women.

The Outfit
Dress to impress. A slinky black dress, perfectly accessorised, is a guaranteed head turner. Especially on a man.

Arrival
You need to create interest. Arrive late to the party, making a dramatic entrance. Crashing your car through the side of the building is a bit passe. You want dramatic impact, not a literal one, though it does reduce the competition.

Pre-positioning
Work the room, meeting everyone, drink in hand. At this stage your drink is a prop, so do not drink it. Take the time to find out basic information - is she a whiner? Is he as exciting as cold, three day old porridge? These things may not affect your enjoyment, but can be problems later. Take your time here, once you have selected your target, you are committed.

Targetting
Once you have selected your target for the evening, get down and friendly with the couple. Keep a light, amusing flow of chat going as you get their partner drunk as rapidly as possible, spiking drinks as necessary. Your aim is a target with seriously impaired judgement, partner totally paralysed.

The Move
Assist your target to get his/her partner comfortably propped next to the toilet as the booze takes its toll. You have a duty to your host to make this as clean as possible, after all. Plus, it gets you adjacent to the bedroom. Do the whole sympathetic hugging thing to your target, who is truly mortified by now. Be a friend, cuddle them, and take ruthless advantage of any and all openings given.
The combination of sympathy and alcohol will lead to a situation that your target may regret in the morning - and you certainly won't.

Emergency Fallback
Very rarely, your target is resistant to the magical powers of alcohol, shame, and the burning need to celebrate New Years Eve by getting their bells rung. In that case - angle for a threesome. And have someone ready to take the fall. (See tags)

Small edit: My current lady is rather upset with me. I forgot this is how we met ...