I'd been wondering the same thing. I'm getting my 4 week old back into EBF after a rough patch (lots of nipple pain, baby is a sleepy feeder and was not gaining weight well) and have been bringing him into our bed at around 6-7am when he'd wake for the first "real" daytime feed. This would normally give me 30-60 mins extra snooze time as he'd nod off as soon as he got close to me and stop asking to be fed. I decided this was a bad idea as I was in danger of letting him sleep through the feed time (one day we slept up until 10am - I sorely needed the sleep, but that was too long a break without feeding or expressing).
I got a bedside crib last week and for the last 2 nights have had an unplanned change of schedule. I've been going to sleep around 10pm, husband brings baby to bed around 1am when he awakes for a feed: as I'm BF now this feed takes longer than the formula feed used to, so I'm awake with him until about 2.30am. I've then expressed from the breast he didn't feed from while he sleeps. He goes into the crib and wakes me around 6am with early hunger signs. I bring him into bed and we have been sleeping in until 7am. This means c.5 hours with no feed, nice sleep for me...but is this a bad idea for keeping up my supply? I'm telling myself he can't be hungry or he would let me know!