Our New TT (May-2020) has a Electric/Propane water heater that has become very noisy lately. If only it were not right next to the bed. But it is and the 2' proximity with a very thin wall for seperat...
It will stay warm in the tank all afternoon. If you use hot water that is in a tank that is turned off, then just turn it back on to warm the cold water that just got dumped into the tank.
Then turn if back off.
I have camped many years. Never needed piping hot water overnight, but everyone is different.