Advice for 1st time mom with the switch to no formula at 12 months

So I know once my 11 month old turns 1, I should stop bottles/formula. So my question, when we first wake up, should I give him a straw cup/sippy cup of whole milk to hold him over? Because daycare doesn't do breakfast until 9am and I drop him off at 6:30am I am worried he would be hungry before that, because he always has a bottle before we leave. Obviously he would always have water but thats not enough.

I have to leave my house before 6, waking up at 4am to make this possible as it is just to make it into work before 7. There isn't any time for breakfast before we leave. I dont think he would want to eat as he is half asleep that early anyways.

Side question, how much water is too much water at his age? I like to leave him with his sippy cup if he doesn't drink alot with his meals. And some days it seems he's thirstier than others he'll try to drink out of an empty cup so I'll give him more. I don't want to overdo it or not give him enough. Thanks in advance, everything I read is different, I would rather hear from experienced parents please!