In two weeks I drank 5 gallons of porter that I had sitting in a secondary fermenter for about 4 months. I am so sad that it is gone, but so happy that it tasted so good. It was about 8% abv and tasted so smooth, I cant even begin to talk about it. It was a bit filling though, you could skip dinner and get down 3 a night, but that was more than enough.
Higher Abv and beers with more hops do better sitting for a long time, don't worry about it and drink a beer.