I think using your oven at 170F would be doable and as I mentioned SV. I have not seen any info on it but if you wrapped a brisket and placed in cooler it might stay in the proper range for 12hrs since you are putting it in around 200F. I see references of 10F lost in 4 hours so, for 12hrs that's 30F (200-30=170F). Some guys have compared the expensive coolers to cambrios and apparently coolers work quite well but the cambrio is designed for hotel pans etc.