I bought a Cocoon silk sleeping bag liner and an Exped utility mat and tried them out last night. I bought the mat with the notion of using it to protect the tent floor from the dogs' nails, but I used it alone last night to see if it would work as a sleeping pad. Turns out it's a bit thin for that. The liner is nice - good stand-in for a bag on a hot night.
Nice morning - woke to chimney swallows and cardinals.