Lucky me, one of the Costco's nearby always has untrimmed whole packer briskets in stock. It was 17.6 LBs but I estimate I trimmed around 3LBs of fat off of it before seasoning with salt, pepper and a smidge of garlic.
It was set on the XL at 10:30 PM at 225 grid/250 dome. As of 9:00 AM I bumped up the temp to 235 grid. Internal temp is now 164 and slowly climbing out of the stall. Looking to serve around 6:00 PM.