I'm a side sleeper who needs an inflatable pad. Right now I'm using the big agnes insulated air core. I'm switching to a tarp and bivy from a tent. Since the pad is so big, it won't fit in the bivy. I want to try and still use the pad underneath the bivy. I'd use a small foam pad if I could get any sleep on one.
Any suggestions on how to do so while avoiding punctures? I was considering using some type of ground sheet, but I didn't know what type of material to use and how thick I should make it.

