I would cool it down quickly and reheat it before serving. If you try to hold it that long it will be too cold. If you put it back on heat it will be overcooked.
Reheating will work out well and you can relax. We have all been right where you are.
Great job on the brisket. It looks like it is gonna blow their sox off.
Jim - Another transplanted Texan
Former KCBS CBJ
Large and Medium Big Green Eggs , Black 18.5" WSM, Blue Weber Performer - Stainless, Green Weber OTG Kettle , Brinkmann SnP Pro, and a Stainless UDS. One retired Portable Kitchen grill.
Red Thermapen, Maverick ET-732, EdgePro Apex Sharpener.
Avatar is the original 1951 Weber Kettle