I think you have to change your expectations when you are with a toddler. Life with a toddler is exhausting! I agree with the backpack suggestions (we use a small LL Bean day pack at Disney) and the Combi stroller suggestion. Our Combi weighs something like 12 lbs and folds up with a strap to carry on your shoulder. I can't imagine if we'd taken our Graco MetroLite (which is my favorite stroller at home). Our DD did well at 11 months last year taking naps in her stroller (we even have a picture of Donald autographing a Disney print "to Sleepy" b/c she was napping while DH got autographs!) and we are keeping our fingers crossed she will for this year's trip, too (at almost 22 months).