We usually don't do it when staying in the World... we're usually in an onsite resort and it is easy to get back.
When we go to DL, though, we usually go when dh is staying in Pasadena on business. So we get up at the crack of dawn and take a long drive over, getting there at 8am, and stay well past the fireworks at 9pm. It is amazing but exhausting. You survive by just chilling out when you can. In the afternoon, find a sitdown restaurant or counter-service to relax in, or kick back on a bench for a while. DD napped in the stroller. Then when you're recharged, hit some more attractions.
Problem is, the next day you are absolutely ruined for anything else.
But when we go to WDW, we're usually there a week and we all love to swim so we usually take swim or nap breaks and don't push it to much. If anyone in the group starts to feel like the fun we're having is too much work, that's the cue to chill out.
We have been known to stay the day at MK once or twice, just because nobody wanted to leave. But usually the next day will be extra laid back in our touring or we won't tour at all.
LEAVING TOMMOROW!
