Q: What if a cup of milk and a gallon are different temperatures and they are mixed? Would temperature not be extensive?

Flexi Says: After mixing two different samples of milk at different temperatures, the combined volume will eventually have the same temperature, which is the average kinetic energy of the molecules. Now, if we split this sample into two parts, they will still be at the same temperature but their volumes will be different. This explains why volume is considered an extensive property and temperature is an intensive property.