What is the min and max oil temperature

It's always hard to find an end all be answer to your questions because there is no one size fits all answer.

Understand that when you measure your oil temperature, you are measuring the "average temperature usually in an oil gallery just post oil cooler and oil pump, but without any load on the oil." If you could measure the oil temperature when it is under stress, say in a camshaft/lifter interface, you would find that the spot temperature is much higher than the average temperature, but only for a micro second, then the oil mixes with other lower temperature surrounding oil and averages out.

Oil will oxidize/degrade at room temperature, only the reaction rate is very slow. As the temperature and pressure increases, the reaction rate increases, especially when the average oil temperature gets above about 250°F for any length of time. The longer oil stays hotter the faster it generally degrades.

Chumley

Don't forget as well, what we might think of as "hot" is all relative as well. Given just how hot the combustion chamber can get under a severe load and or high speed, oil temperature, even if at 240F would seem downright "cold" in actually.

I also thought that oil could see an average of 300F in severe climates and/or conditions, hence why we look for a product with a relatively high flash point, right?

dad flash point has nothing to do with operating temp of oil it is only good
in one way as a method of compariosn higher usally means a better or higher quality base stock.
operating temp in a engine showld be minimun for 212F to aprox 240F
bruce

If Max bhp is achieved at a water temp of say 90-100c then then the oil will normally be at a slightly higher temp.

To run at a higher water temp will reduce bhp but additional cooling adds weight, so a trade is made between weight and bhp.

Oil will usually run at 90-150c which should not be an issue for synthetic especially ester based, a mineral perhaps should be limited to 130c.

If the oil is run constantly at 110c and above an oil cooler will help maintain viscosity.

To help maintain viscosity at high temps and deal with fuel dilution (thins oil) with carbs or endurance racing then a thicker viscosity oil can be used. This has a downside as a thicker oil runs hotter. An alternative is to use a better quality ester based oil (usually race oils eg Millers, Silkolene, Motul, Redline).

Ok, I understand you both MGBV8 and bruce381. Thanks for the clarification and reinforcment of how better basestock=better product.