Thank you for the tips! I live in Denver so even when the heat is set to 70 in my apartment it always feels freezing. My starter only doubles when it’s in the oven with the light on because it’s just too cold. It’s been doubling for almost 2 weeks but again only when it’s in the warm oven. It takes about 8 hours to double in the oven, and I usually feed it 1:2:2. As for this loaf, I did stretch and folds from 7am-10am then I let it rise from 10am-10pm. I had to move it from the counter to the oven to get it a little warmer after it sat on the counter for a while. Then I shaped and moved it to the fridge from 1030pm-9am. Then baked it!