The scenario you describe is fine in normal climates. Water is a normal product of combustion, and unless the engine reaches full operating temperature the water in the combustion gasses that blow by the rings (all engines have some level of blowby) can condense on the cooler metal surfaces and run down into the oil pool in the oil pan. If the engine is at full operating temperature, the metal surfaces are warm enough to prevent condensation and the gasses in the crankcase are warm enough to retain the water vapor and carry it through the Positive Crankcase Ventilation (PCV) system up to the space under the valvecover to be reingested into the engine.
The reason I mentioned the climate is that when I lived in North Dakota we had a terrible time in the winter even getting our engines up to operating temperature. We had to plug the cars in overnight (engine heaters) and put cardboard or blankets over the radiators. Even then it takes a while if the car’s been sitting all night at -40F. If you live in such an extreme condition, it’s a good idea to let the engine warm up some before taking off (not recommended in more normal climates). If you live in such a climate, it’s also a good practice to change your oil more often than the owners’ manual recommends.