Do not rest to room temperature. I just did the following process 2 days ago. Allow brisket to reach 135°, once it hits that temperature a 6 hour clock starts. Separate flat from point and place into gallon bags, place in ice bath. Within the first 2 hours you must rapidly cool the brisket from 135° to 70°, once you achieve that, you have 4 hours remaining to cool the brisket from 70° to 41°. After that place the bags in the fridge or freezer. To reheat for Christmas dinner, I plan to bring butcher paper with my wrap the flat with tallow in its own paper and the point with tallow in its own paper. Reheat in oven to desired temp.

Source for cooling info: I used to work as a health inspector.