Despite our lack of a sled we tried to improvise using a storage bin lid. Unfortunately, it didn't work too well even with our sloping driveway.
I had a flashback of using a shovel as a sled for the few times we went to the snow in the mountains as a kid growing up in California. So with our wide scoop shovel we gave it a go and it worked wonderfully! Jonathan got his workout pulling the kids around and the kids were giddy with delight for the increased speed and doughnuts they were spun into by him. It was a good morning enjoyed by all!