Spent 3 nights shivering in a 20 degree bag at Pictured Rocks before I figured out the real problem
I camped for like 4 years thinking my sleeping bag was just not warm enough for cold trips. Every fall I would wake up at 3am freezing and blame the bag, then go read reviews and almost buy a new one. Last October at Pictured Rocks in Michigan it got down to 28 degrees and I was cold AGAIN in a bag rated for 20. My buddy Jake finally asked if I was using a pad with an R value above 2. I looked it up and mine was an old foam thing at R 1.3, basically a yoga mat. Bought a pad with R 4.5 for $90 and slept warm the next trip in 24 degree weather with the SAME bag. Now I wonder how many people out there are out there swapping bags when the ground is stealing all their heat. What R value do you all run for fall camping?
R 4.5 is the sweet spot for fall. I run a 4.0 to 5.0 and it fixed the same 3am cold problem you had. My old pad was R 1.8 and I froze at Dolly Sods in October, blamed the bag for two whole seasons. The pad is half your sleep system and most folks never check the R value. Ground pulls heat out of you way faster than air does.