I sleep better when in the woods if I have on my baselayers, esp tights. Even if not needed for warmth, I like how they keep my quilt or bag cleaner. Also tights help me avoid that "sticky" feeling of my legs touching each other, which has bothered me occasionally as a side sleeper.
Are thin silk layers durable enough? I don't want this pair for warmth, but for the above reasons, and even my thinnest poly or wool layers are too warm sometimes.