In my home, their bodies are still on "routine" for about 2 weeks into the summer.........then the later nights begin and so does sleeping longer :O) I let this go for the most part for most of the summer......the way I get back on track:
Starting 2 weeks before school starts, i begin a 9:30-10 bedtime (if we've been staying up later than that).......and I wake them up around 8:30-9 the next morning.........I do this for about 4 days until they wake by themselves.
Then about 4 days before school starts I make them lay in bed at 8 to watch TV til 9am (if they last that long). They usually wake up by 7:30 by themselves by doing this (even though they need to rise by 7).....The hard part about doing this is not scheduling any "last minute summer fun" before school starts :O)
I've been doing this for about 3 years, my oldest now being 13........we'll see if it works this summer :o) I've had less "tears" the first week of school by doing it this way, though, I can attest to that! :O)
Have a fun summer!
~N. :o)