Dear disneysteve,
I have yet to go to WDW. I have no idea about these things. I've read about how 5, even 6 year olds sometimes conk out after a day of park rides and what-not. I have, in fact, seen that happen earlier this year in NYC on the streets. Hitting the pavement after a long day, she begged to be carried or to have a stroller. So, it's an insurance policy.
I take it you've had experience in the parks near the time that we're going (late April) and, if the canopy is not all that necessary, then I suspect we can just go with the limo's rental stroller. It's a Costco umbrella stroller type.
I don't know if she will or will not sleep in any stroller, but I know whenever she's exhausted, she likes to be carried.
I'm going back and forth between renting the cheapy Costco one from the limo service and bringing our own decent MacClaren.
I'm leaning toward renting it down there....
KIS