Your thyroid numbers look really excellent. We're all jealous. TSH varies with any number of factors including the time of day the blood was drawn. I wouldn't worry about the variation at all.
Your thyroid labs are great. And your cortisol levels are good too......all within range except for the midnight one, which could be showing low blood sugar during the night. Something is stressing your body during the night, which can be like I said above....low blood sugar.
If your adrenals were weak, it would have showed during your other times. Make sure you are taking enough Complex B's, Vit C, and perhaps an adrenal adaptogen. I take an adaptogen so that it regulates and supports your adrenals when you are underactive or overactive.
Try have a protein snack before bed to hold your glucose levels through the night. Might be worth checking your glucose levels as well.