Not all of them made it to the customer.
https://www.jeepgladiatorforum.com/forum/threads/spectacular-train-wreck-destroys-jeep-gladiators.18831/page-1
Seems like the RAM still has this option.
https://www.ramevforum.com/threads/powering-air-conditioner-in-rv-using-bed-plugs.412/
https://www.cumminsforum.com/threads/2026-itch.2623650/page-6
Sounds like the cabin is lacking insulation. Is the Jeep still under warranty? We can tell a difference switching from the hard top to the soft top, but don't have any cold weather issues with the hard top on. Cabin warms up quickly and maintains the temperature.
I mistyped because I'm still daily driving the Jeep. However, we have another vehicle for long trips to save miles, as we put on 21k/year for the first five years.