Although our fasting levels are seen as important by many and they do show how far up the diabetic ladder we have climbed.
They are the one thing we have no control over, we can't stop our liver from doing it's job. I've seen lots of suggestions of ways to fool the liver into not releasing it's glucose, a glass of wine on the evening, a protein snack as soon as you wake, to name just a couple.
The problem is not that our liver takes the opportunity to get rid of some sugar while we sleep.
The real issue is that our liver has too much stored sugar.
So rather than concern ourselves with fasting numbers we can't control, concentrating on something we can influence is more likely to improve things.
reducing carbs as much as you can , keeping any rise after meal's to within 2mmol will reduce how much sugar is stored away to be released when you're not looking. If you can do a little more exercise that will also help with reducing your personal sugar pot.