caveat, I'm new to fatbiking, so I'm very curious to see how low pressures with fattubes goes for me. Previous low pressure stuff has only been up to 2.5 in tires, winter riding, with no problems, pinch flats nor tube creep. Can't recall pressures, would lower for snow conditions by feel, I suspect 20 psi ish. Light rider though and not jumping off curbs etc.
I am also curious what others run. But I also understand there is a lot of personal preference and conditions vary greatly.
I typically run 6.5 psi on 4.5" tubeless. My buddy thinks I run too hard. He rides tubes. Went closer to 5 for sand dunes and 10 for slab. Have not been on snow.