I held tuff at a permanent bunk. I waited to be able to sleep while loaded, no matter what. And I often did sleep while loaded. That meant 9 feet for freight, not even a quarter inch more. So 2 pallets. I can count on one hand how many times I missed out on a load because it was 3 skids and didn't get a one of two skid load instead.
Unless things have changed dramatically, most expedite shipments are 1, or 2 or more-than 4 pallets. 3 and 4 pallet loads do happen, but not nearly as often as the others. I admit I haven't talked with any dispatchers in quite a while about it. And the last to haul 3 and 4 pallets may have altered the landscape of expectations. But even if 3 is the normal minimum, I'm still gonna sleep while loaded.