It depends what I've been doing in the day, frankly. I may have my basal set perfectly for a fairly inactive day, but if I have been doing sport my blood sugar can drop during the night. So, for example, last night before bed my blood sugar was 4.7. This morning, when I got up, it was 4.7. Seems perfect? But at dawn it was 5.0, and before I went to bed I ate an apple - about 20g carbs. If I hadn't I would have hypo'd, I'm sure. I knew because I had been fairly active in the evening. If I had done more vigorous sport during the day, I would have pushed my blood sugar up to 7.0 before bed. An alternative is to reduce your basal rate by some percentage or other over night, but I am less skilled at judging that so far. But I agree that 10 is too high, and your basal probably needs reduction. But when Type 1s are "hypo-averse" and keeping their blood sugars high, it can be because they haven't learned to manage the combination of exercise and dosing of insulin. It is predictable, once you realize the relationship is there. But you have to see it first.