I agree with Keith that I'd probably let it ride. I've made some great stouts in the 1.083 range.
I've also added sugar to the fermenter to bring the OG up to where I wanted it, so that is a viable route if the OG/abv is important to you. I've added the sugar direct into the fermenter, all at once, no problem. Maybe not a full pound at once, but at least 1/2 pound followed by 1/2 pound the next day. I've had no issues pouring it in dry, no need to make a simple syrup.