Common sense and experience will help here. If I'm doing a climbing ride on a hot day there is no way I can get enough water in and frequently drink over 200 ounces and still get dehydrated.
On a flat ride on a cool day obviously I need a lot less.
The other thing is to prevent an extreme imbalance of minerals by eating and/or taking electrolytes.

If you wait until you are thirsty you are making a mistake, especially if you have a bunch of hot climbs ahead.