How long has Ice been displaying this behaviour may I ask?
Is he sleeping more, eyes closed and not as active?
What temperature is the room where he is caged, has he been eating, drinking, normally and what is his poop like? Runny, green, poop is a sign of trouble as is a fluffed up budgie usually . They do not sit fluffed for no reason. An avian vet visit would be the best way to go regarding your little Ice. I hope all is well soon.
I haven't had him very long but he doesn't sleep too often. I'd say the temperature is between 18-22 degrees. His eating is normal and his poop too. I haven't seen him drink... How often should they drink?
Ok budgies do not need to drink as often as we do , they usually will only drink after their first eating session on waking and perhaps a little sip every now and then. they need the water to be room temperature they don't like water that is too cold.
If your budgie drinking a lot then it is a sign of sickness in fact.
They also need a good amount of sleep, a uninterrupted night time sleep is essential for their wellbeing and health. Budgies do not have good night sight so the tend to start settling once the sun has gone down in the wild.