Gauge your intake and drink steadily on your ride. Just keep sipping. If you don't have to stop and "return some water to the wild" about two hours into it, you're not drinking enough. A bladder in a tank bag or camelback works pretty well.
Since you have an overnight to rest and recover, shower, etc., go for it, just drink a quart of water (yes you can) before you start and stay hydrated as you go. If you wait until you're thirsty to drink, stop and take a break because you're running down.
It's safe enough, I just don't ride long distances to meetings and stuff where I am supposed to look and "smell" good upon arrival.
Oddly enough its been in the 70's - 80's here in GA the last couple of weeks, but 90's are coming this weekend.