It all depends on how much your basal drops your readings over time, and if you feel like your levels are apt to change based on injections close to bed time.
Personally, i get nightmares if sugars drop below 4.5mmol/L. Throughout the day i am totally fine at 4.5mmol/L but if they are 4.5 or lower while I am sleeping i tend to have very vivid, strange dreams, usually nightmares lol
So i usually make sure that I go to bed at a reading around 6.5mmol/l and that usually holds pretty steady through the night and i wake up around 6