We just plan to go and have fun! (we'll be there May 28-June7 - all 10 of us, including 5 adults, 5 kids ages 7-10). I know Mem. WE might be crowded, but I'm so excited to be there I just don't care. We're even doomed (just kidding) to visit MK Sat., the 29th, just because it's our first day, and because I can't imagine any other park to begin with at Disney, I don't care. After all, how can I complain when I'm actually at Disney? I know I'll love the magic, no matter how many thousands I have to share it with!
My suggestion is to just let your kids set the pace. No hurries, running from ride to ride, etc. If they want to stop and run through the water fountains, let them. If the lines are too long, head somewhere else. There's nothing you absolutely have to do, no ride that your vacation experience would be incomplete without. On the reverse, if you have to ride something, the line is long, bring surprises (I have dollar-store bubble stuff, etc. for line entertainment). Or grab an ice cream to enjoy while you wait.
And when they're tired, head back to the hotel pools and relax. You'll get so much more out of your vacation that way. I feel bad for the families that drag the tired kids throughout the park, some wailing, just so they can be sure to see and do everything. Afterall, you have a lifetime to enjoy Disney, right?