I was thinking the same thing myself as our times will change soon (I'm in Oz). I have a 6 year old as well so have some memory of facing this with him. You could change his times over gradually (15 minutes or so) but I think I just used to go with the flow and woke him earlier. For you, it will probably mean putting him to bed later and slowly trying to get him to sleep longer in the morning. It might have been a little messy for a few days but I think generally my son coped really well and it really only took a day or two to adjust his body clock. We have also done this when travelling. I find that at the moment my 4 month old is waking a bit earlier anyway because it is getting lighter earlier so in some ways, it might be a natural change for them. (your LO might sleep longer if it stays dark for longer). Once when we went to a different state with about a 2 hour difference, I didn't bother changing his body clock because I thought for a week or so, it would be easier just to live with the different bedtimes. The worse situation is when you live somewhere where they DON'T change times because then dawn comes at 4.30 or 5am and the child wakes up because its getting light then. we had to get blackout curtains then. Anyway, am wafting on. Hope that's been of some use to you.
Jacqui