Personally, I try to go to bed with a bg level of around 6-7mmol and try to keep it at that level throughout the night by adjusting the basal rates on the pump. A bg level of 5mmol can easily turn to 2-3mmol during sleeping hours without a pump and even with one, a bg of 5mmol is a tiny bit too near to hypo land and no one wants to have a nightime hypo and chance whether they will wake up or need help.