That's 3.5dl, a topped up normal glass off water. Unless you've gone up to pee several times per night, if you don't have issues with retaining water, that's a completely normal amount of water to drink upon waking up and getting to the lab. If one wasn't somewhat dehydrated before sleep and didn't loose a substantial amount during the night, 0.35 - 0.5 liter of water is completely ok to drink and certainly wont be the reason why one has a high hematocrit/hemoglobin.
One can have a poorly functioning RAAS, or issues with ADH secretion or kidney issues, etc. it's too intra individual to give any cookie cutter advice for fluids intake. You could also just as well drink too much water.
OP said he drinks plenty of water through the day so I'm presuming he was adequately hydrated before bed.
And I don't understand why all the fuss about hydration if he had 1100 ng/dl at through, meaning he's around 1600 - 1800 at peak. Way beyond normal physiological levels, which should be around 550 - 750 ... And let's not forget that his hematocrit and mchc are both normal. He isn't dehydrated.
@immaty your hemoglobin and rbcs are high due to androgen excess. The low estradiol, only isn't helping you much with extracellular water retention, so lower your Ai dose or cancel it completely.
What is this anyway, a cruise/low dose cycle?