Okay, I hate to do this, but I have to disagree with previous poster. I don't think it's unreasonable for a 7 month old to have one night time breastfeed. Although some (most even) can go without night feeds at this age, especially with bf where you don't know how many ounces are taken in during the day, I would be reluctant to completely eliminate night breastfeeds.
When I was sleep training around this age I picked one window during which I would breastfeed. So, for example, at this age, if it had been 4-5 hours since last feeding, and DS woke up, I would feed him because it seemed reasonable to me that he would be hungry. If it was less time than that I did pu/pd. If I feed DS in the night, I would take him out to the living room (still totally dark), so that we weren't sitting in the chair we used to nurse to sleep in, feed him, and watch carefully--as soon as his sucking started to slow, then I would go put him down while he was still awake and do pu/pd until he fell asleep in the crib.
Personally, I'd ditch the dummy. Babies, like all of us, have little partial awakenings during the night. They expect everything to be the same during a little waking as it was when they fell asleep. If all is they same, they just go back to sleep and we never even know they were awake. If, however, something is different, they will generally holler and insist that we come and return things to how they were when LO fell asleep. This is why dummies create such a problem--LO falls asleep with it in mouth, it falls out when LO hits deep sleep, when LO has a partial awakening, LO realized dummy is gone and wants to be replugged. I'm not sure it's realistic to expect a 7 month old to find and replace a pacificier in the dark . . . I could be dead wrong abou that.
Are you using pick up/put down? What are you doing to help LO settle during these wakings if you don't bf or give the dummy.
Sorry to be contradictory . . .
Bethany