Your dreamfeed sounds right- baby is supposed to be sleeping. Bear in mind though that your lo is 7wks so going for the 5.5hr stretch is pretty good!! And I wouldn't worry too much about how much he takes during df since he still sleeps for that stretch of time. In time, he'll do without the df anyway...
I actually used to wake my lo around half 10-11ish pm to do the night feed (because I wasn't sure how to do df) and she would still wake up around 4-5am for a feed- sometimes full feed, sometimes partial only. For that night feed, she would take about 2.5-3oz (her full feed during day was around 3-4oz). When she was around 2.5mths or so, while she still woke up in the wee hrs, she would refuse to feed past 2oz or even 1oz so that was when I would give her the pacifier and she would then sleep thru to half 6-7am.
I started giving her the real df (ie, feeding while she's asleep) when she was about 3mths and I do this 11.30pm every night. Sometimes of course, she wakes up during the feed but either way, she still sleeps thru til 6.30-7am, though not without her stirrings around 5am in which case, I just give her pacifier. She's 4.5mths now and going thru her many developments so her wake ups are a bit inconsistent as she tends to wake herself up w/ her hands etc. Even now, she only takes between 2.5-3.5oz for dreamfeeds (during the day on 4hr easy routine, she takes 6-6.5oz each feed)... I know that the baby whisperer says that babies usually take full feeds during df, but she seems to be ok w/ that amount.
Don't worry if he does wake up once in a while, sometimes that can't be helped. The main thing is that he sleeps for a good stretch of time after the df. You'll find that he'll be sleeping longer as he gets older and his tummy gets bigger... Eventually, he'll even refuse the wee hr feed and you can just give him the pacifier to help him sleep thru til wake up time.
Sorry if I rambled on a bit, but hope this helped!
