My DS was 8lb 1oz when he was born but gained a pound a week or so and by 6 months was off the charts for weight and 91st for height. I think he was about 25lbs at 6 months.
He was exclusively breast fed, on demand, and was probably feeding every 3 hours in the night and this got worse at around 4-5 months which lead me to weaning him a couple of weeks early (at 5.5 months). It is tough, I know! He then dropped back to 1-2 feeds overnight until he was about 10 months. He took to solids like a dream and fairly predictably wolfed them down.
DS is now 16 months but looks older. With all the crawling and running around he does, his weight has totally plateaued and he is now 29lbs - so only about 4 lbs heavier than 10 months ago. Back on the chart for weight, still 91st for height, and he's a really healthy, active little lad. And if he is poorly and off his food, it doesn't worry me too much because I know he has a bit of emergency chub for just such occasions. 
At about 10 months he was eating a very full diet of solids, as well as having milk feeds in the morning and evening, so I swapped the night feeds for cuddles and water if he asked. He quickly dropped the habit and started sleeping through until 5.30am-6am, and from about 14 months he goes 7.30pm-7.30am. I think at that stage it was habit, but I think you will know whether it is genuine hunger because there was no way he would settle if he wanted food.
If I were you, I think I'd wait until he was eating solids before trying to drop his night feeds. My feeling with DS was that he was genuinely a big, hungry boy and that food was his thing. It wasn't until I was convinced that he was getting plenty during the day that I thought that I could get him to drop night feeds without a fight.
Good luck OP! It's not easy, I know, but in a few months when your LO is sleeping through, this will seem like a distant memory.