I have LED puddle lights (dim red ones) and usually leave the interior lights that can be turned off, turned off. As far as I know, those other interior lights I have no control over (armrests, keyhole) are LEDs. It's the systems that are activated whenever a door or hatch is opened that slurp up that additional ampere of current, not the cabin lights. Cabin lights, especially if they were incandescents, would be on top of that. I don't think having additional doors or the hatch open changes much - the big difference is if any one of them is open.Yes I saw that thread and it's the one I was remembering.
The draw is there but only up to alikely max of 1.0 for the hatch and if you add interior lights that are on, doors that are open and play some tunes, I can see the battery draining after a number of hours.
I think the best working solution is to replace the interior and puddle lights with LEDs, don't go crazy with the radio but in the end, have a jump pack.
"Playing tunes" involves activating another couple of levels of systems because the key has to be inserted (one) and in the Acc position (two), so will likely use more current than just the power the radio consumes. I should probably test how much inserting the key, then turning it to Acc, then turning on the radio, cost - thanks for the idea!
These days, a jump pack is not a bad idea. Keep it charged, though, so it will work when you need it!