Is a double stroller a must for Disneyland Paris?

We will be flying to Paris next month with our 4.5 year old and 7 month old.

I'd love to not invest in a double travel stroller. We have the double setup for our Uppababy Vista already, and a single travel stroller. I'm not worried about the airport or our time exploring Paris proper, but I'm concerned that I'll end up baby wearing a ton in the parks and we'll be hot and miserable.

The 4.5 year old is 38 lbs, almost 40 inches tall, and has pretty severe anemia related to a medical condition as well as slightly low tone, so she tires easily. The baby is currently a little over 18 lbs and at least 28 inches. He's also in the verge of crawling, and just generally a big, strong kid already.

Am I insane to try this with just the single and the kids taking turns whole my husband and I trade off with the baby?