What a great question! I have some initial thoughts, but I am sure others will add some too. As a visual thinker, I immediately thought of a circle of kids taking a nap with a central camp fire - so the kids are like the spokes on a wheel, or the petals on a flower... But okay, some specifics. A minimum of Sleeping bag, and pads for sure, but with little kids you don't need a super plush sleeping pad. In my experience kids will sleep on anything as long as they are warm, so a simple sleeping pad like a ridge rest, or z-lite should work. Temperature ratings for kids bag can be tough as very few use the EN rating system. You might have to hunt for an accurate zero degree bag for kids. You could use a sleeping bag liner to boost the temp of a kids bag, but if you find a good reliable kids bag you probably won't need a liner. 

Instead of a tent, I envision oversized tarps that could have several kids under them. No walls to trap viruses, but a roof that will protect from rain and snow. 

Done right, these kids could be really Snug and have an awesome outside nap!

At REI, we believe time outside is fundamental to a life well lived.