It's not ideal to re-use yeast from one high-gravity beer to use in another. Better would be to go from a low-gravity to high-gravity. That said, if the yeast was healthy, it will probably work. Not sure what you mean by "step up". Usually, that's something you do with starters - feed them more wort in steps to build up the yeast mass. You don't need to do that if you're re-using yeast from a full batch.