I am such a moron! I was doing 3 things at once when I wrote that. I meant to write carbonation, not fermentation. Of course it takes longer when ita a higher gravity to ferment. Wjat I wanted to ask was does it take longer to carbonate (bottling) when the beer has a higher ABV?
My guess would be that it would depend on the yeast strain and the amount of residual sugar and the temperture it was being stored at. Different yeast strains react differently to alcohol levels.