The scientific data...for what it's worth...
Having worked in the medical field most of my life...all babies are individuals, the length of time they will sleep at night is partially a function of how much they currently weigh, and the length of time they will sleep at night is partially due to the brain formation which regulates the production of melatonin (a hormone that helps control sleep by light and dark as seen by the eyes, whether awake or asleep).
Weight plays a role because a larger baby (generally the data I've seen hovers around 8+ pounds) can take more calories in during waking hours and at that last feeding before bed... and those calories will hold them over longer.
Whether the extra calories in cereal plays a part in that...my jury is out on that topic. The intestinal lining often cannot process such large molecules (also why we don't normally feed cows milk to newborn humans) at a very young age.
My daughter was more than 4 weeks past her due date, weighed more than 8 pounds at birth and slept 11 hours at night from the first night she was born. And she was continually nursing on demand during her waking hours. By 8 weeks old she needed more calories than breast milk (and all breast milk has different nutritional content so you have to go with the individual needs here) and I started her on cereal...during the day and with a spoon. Rice constipated her so we changed to oatmeal cereal. By the time she was 4 months old she had acclimated to all the usual fruits...bananas, pears, apples, ...that I could make for her in addition to the cereal. Then she wanted everyone's milk glass at the table by the time she was 9 months old...so I tried it. Biggest mistake I ever made with feeding her. It took weeks for the diarrhea and vomiting to stop. To make a long story short...my daughter could process some things like cereal and fruit at a very young age, but something so seemingly simple as milk gave her guts a run for the money.
Melatonin production is important because until the day / night and sleep/ wake cycles are established it's a futile effort to try to regulate their schedules. So essentially as the baby gets older and the brain matures the cycle should establish a good sleep pattern. Now if everyone has been walking around the house on tiptoes while the baby sleeps until this point and then you suddenly drop the frying pan... I did laundry, vacuumed...all with her door open while she slet. That kid has slept through earthquakes and a helicopter landing right outside her bedroom window! So it pays to practice good sleep hygiene right from the start (do an Internet search on "sleep hygiene" for more info). Try to also establish normal light and dark cycles. You can play with that one a bit. If you need to go to bed earlier than it normally gets dark out, take the baby into a darkened room earlier. If you need the baby to be awake try keeping bright lights on even though it may be dark out. Just remember that you are messing with nature and it can backfire on you. Sleep cycles that are established in young brains may be difficult to change later on.
And lastly, something my pediatrician told me at the first appointment...whether you breast feed or bottle feed, always be sure that the baby is awake when you put them in the crib to sleep. If you nurse them until they are sleeping and then put them in the crib they have a more difficult time learning to put themselves back to sleep when they wake multiple times during the night, as all humans of any age do. So teaching them to put themselves to sleep from the start was key for us getting the baby to sleep during the night. And try not to use a pacifier to get them to sleep...when they wake during the night they will need that pacifier to get back to sleep...and it probably got knocked out of the crib and someone (read: MOM) will have to get up to retrieve the pacifier from under the crib so the baby can go back to sleep.
But all babies and all mothers are individuals and should be treated as such. What works for one baby doesn't work for all. The scientific data only represents "most" babies, not "all" babies.
Good luck!
