I really hope this "desperately need to fall over and sleep for 1.5-3 hours, up for 1-2 hours, able to sleep for 4-5.5 hours" thing gives way to "able to sleep for 7-8 hours" soon. See also "I wish my workplace had a designated nap room, or my working conditions were otherwise more flexible such that getting back to sleep were less vital."
I want to say more, but am not sure what precisely.