@slothrop forgot I took pictures for you.
! Not recommend, just what I do !
I often have a small, light ground sheet (Tyvek or Polycro), redundant but nice.
My diy bivy goes on top. It’s very lightweight ~5oz (UL dyneema & ripstop).
One of my many diy or modded pads goes inside the bivy (pictured on top) with a space blanket under it.
Then my summer or winter down quilt (summer one this trip) goes inside and I’ve been using car wash sponges lately for pillows.