We just got back yesterday, with kids 7, 5, 2 who also have bedtimes of 8:15pm. We had a two hour time change when we arrived, and our kids never adjusted since we were only there 5 days. So we were up between 5:30-6:30am California time (7:30-8:30 our time). We would get to parks right when they open as the lines aren't as bad then. We never left the parks all day. Only my 2 yo naps still so he would just fall asleep when he was tired and we would either lay him in the stroller or hold him, finding a bench to rest on when needed, and it worked out well, the rest could still ride. Or catch a show so he could nap while we got to enjoy. Saying that, at 8pm (10pm our time) the kids were tired, we didn't see the fireworks at all, but they didn't seem to care, I guess if you have never seen them you don't know what you are missing. I would have liked to see them, but that's fine. We left the parks around 8:30pm and crashed immediately. I think we we would not have had the 2 hour time change, we could have made it up later and still not have left that parks. So take that into consideration if you have a time change! Have fun, you'll love it!