My last snake escape was during winter in our unheated and non insulated apartment. I'd say the temp inside was 50-60F. She was gone for I think five days before I found her above the non working (no heat and super drafty in the wall too) heater inside the wall. Since it's summer, she should do just fine. I tried the flour, live mouse bait, heat mat with hide on top, running a heater on low near the mice to warm up that area and push the mice smell around, plastic bags around the walls so I could hear if she went across them, etc. Found her by sheer dumb luck of her falling on top of the heater in the wall from wherever she was climbing to inside the wall. I happened to be in the living room and heard the thud and saw her bit of white and nose poking through the gap.
Best of luck! Crazy things happen and don't lose hope!