exactly this.
I keep mine in a tall 64quart container. Their egg crates stand on end stacked so the frass (poop) falls to the bottom. I've got some heat tape on it and it keeps the hotspot around 96 degrees and gives them a gradient. They breed like mad. I think i started off with 400 in February. Theres a few thousand in there now. They can also take a ridiculously high population density. Probably 5x what i have in there now and they'd be fine.