Hi,
The_Captain - This is one perspective to your question about "optimal engine temperature". Moisture itself evaporates early in the warm up process but its handling is another matter, see below
Firstly it depends on the engine family and its structure. Some engines are designed to reach their optimum cooling system temperature quickly, stabilising the coolant/oil temperature may take up to 20 minutes or so depending on use and ambient etc. Even engines within one family may "breath" differently from another depending on the application
The condition of the engine plays a role especially cooling system thermostat, PCV etc.
These figures give you a guide;
Optimum oil temp typically is above 80C 176F and in a range up to 90C 194F
One engine family I'm very familiar with had these parameters;
Normal 110C 230F
Warning 115 239F
Shut down 120C 248F
My Averages over all engines within the family was 103C 217F
My Porsche 928S4's average oil temp was 86C 187F - this engine has a thermo controlled oil cooler and thermo controlled air flow intake flaps.
Even in the Tropics where I live this engines typically took around 20-25mins to reach a stabilised oil/coolant temperature relationship
I hope this is of interest