With that long of a wait on the ground, I’ve always wondered if folks are allowed to get up and use the lav? Or use tray tables and recline seats, or use the pull out TVs in the bulkhead/exit rows? Or using laptops?
My experience was yes to everything except the pull out TVs, though you are not allowed to form a line for a lav near the cockpit door. FAA/DOT tarmac delay rules actually say that lav access, water, and I think snacks (if catered for the plane) must be provided once the tarmac delay hits the one hour mark.