With Josie, I got a lot of mileage out of playing with her quietly in her room as she was winding down. She was awake, but she wasn't wide awake. As an added bonus, I could watch her cues really well, and it helped me work out ways to keep her ever so slightly still-awake a bit longer at a time every couple days till we were up to a 4-hour EASY.
And not to scare you off, but some babies (like Natalie, who's barely had 2 similar days sleep-wise since she was born
) work it all out on their own By the time you think you've got it sorted, they've gotten older and are ready for something new, like teeth or cutting out a nap or rolling over or crawling, and you have to wait for the novelty to wear off and backtrack.
Meanwhile, I think you're on the right track trying to extend A time. What happens if you at least extend the time between feeds? Oh, and if he's 5.5 months, is it possible he's ready for the very beginnings of solids? Is he interested when you guys eat at the table?
