winter warmer brown ale debachery

So, I took a shot in the dark in formulating a winter warmer brown ale. I used 6 pounds of domestic 2 row, 2 pounds of caramunich, .5 pounds of crystal 120 .5 pounds chocolate malt, 6 pounds of light munich 2 pounds of brown sugar, 3 pounds of honey, one pound of hazelnut syrup, and cascade, 1 oz willamette, and 1 oz cascade hops. The flavor turned out perfect. Light hop, perfect carbonation, and great malt, and flavoring balance. The problem is, it's wayy too sweet. Gravity is sitting at 1.045, despite pitching 3 packs of s04 at it. I'm thinking this beer would be excellent at 1.016ish, with just the right hint of sweetness. Anyone have any suggestions of bringing the gravity of this beast down to a palatable gravity?

I've considered champagne yeast, or another high attenuating yeast, with maybe some Beano thrown in- taking readings until it gets to the desired gravity, then heating the beer to 140 for 20 minutes to kill the yeast, and denature the enzyme. Any other suggestions would be greatly appreciated. BTW, this was a 5 gallon batch.

Follow up questions.

How long has it been in the fermenter?

What temp did you mash at?

Did you bottle already(perfect carbonation)?

Was your yeast particularly old?

Is your yeast an alcohol tolerant strain?
* In this case it would need to be as with this amount of fermentables you're going to be up around %15 alcohol. I haven't actually used any Safale yeasts, but the wyeast strains i use usually top out between 10-12%. It may just be too alcohol rich in there at this point.

I've heard some people add enzymes to restart the fermentation process

You have 21 pounds of fermentables which puts you around 13% ABV. I would not be surprised if the yeast have reached their max alcohol tolerance. 6 pounds of the fermentables, so almost a third, is simple sugars which may be making it difficult to ferment because it doesn't add any nutrients to help fermentation along. Also, I'm not sure if there are any preservatives in the hazelnut syrup you used but if there are then they are inhibiting or slowing further fermentation and there is no way to take them out.

sounds like it would be good over ice cream

What was the OG? 1.150? If so, you're done. 1.045 is 70% attenuation.

Yeah if you want such a huge beer to ferment that low you may need that beano trick.

Good point on the preservatives, I hadn't even thought of that. I achieved only about 60% attenuation, and that just might be why. Perhaps a blend might be in order. In hindsight, I should have also used a higher attenuating yeast for such a big beer. Lesson learned.