Hi Laura -- This is Vicki. We've used various methods. One is to use a regular [warm] sleeping bag, but tie it off half-way down (belt, rope, bandana) so the warmth stays around the baby. Extra pad below, blanket over all. Or cuddle her in with you in your bag (at 8 mos., that's probably your best bet). Got two bags that zip together? All 3 of you. Or make a nest with bags below you, opened, and blankets above. Put her in warm jammies and a hat, of course. If she's an "active sleeper" like our youngest (she was known to actually crawl into my shirt WITH me) use your clothing bags/climbing packs/suitcases/stuffsacks to wall the two of you into a smaller area so she won't get too far away. And you sleep on the outside, against the tent wall. It's kinda short notice, but I was able to find really thick fleece one-piece jammies that worked well (Columbia?). Then when I found that the fleece picked up all the detritus the child crawled thru in camp, I added a set of rain gear over the top of that. Good luck!