I asked my Doctor “why do I pee more at night, and should I stop drinking water before I hit the sack?”
“When you are upright gravity holds water in the lower part of your body. So when you lie down the body (legs etc.) are level to your kidney which finds it easier to remove water.
The second part of your question is simple too.
“NO don't stop drinking water before bed time . As muscles seek re-hydration when too much water is removed there is an increased risk of stroke heart attack or even just simple but painful things like leg cramps. A glass of water before bed reduces that risk.
“Drinking water at other times also maximizes body effectiveness”
A couple of glasses of water after waking up helps activate internal organs
A glass of water before a meal - helps digestion