How can I get my 5 month old to sleep longer?

My 5 month old will eat 'dinner' stage 2 baby food + 3-4 tbp cereal at 5pm and then have a 6 oz bottle at 6:30pm. He somtimes will sleep fine until I pick him up for a dream feed at 11:30pm, othertimes will wake up on his own (hungry) between 10:45-12. He will then sleep until 3am (on the dot) every single night...and wake up every 30-45 minutes until 5am...I have binkied him...given him water..and it will keep him happy for 15-20 minute at a time. At 5am, I relent and I give him another bottle. I KNOW that he can go 6-7 hours without food since he has done it on 1-2 occasions...I am EXHAUSTED....any suggestions are appreciate...cry it out (and I sleep downstairs)...keep giving him water at every awakening? keep binky-ing him at every awakening? I"m out of suggestions for getting him to sleep from 3am onward!!!!