Might be simple, XML and Save data

To begin I have basic Knowledge of C# and Unity. My question might have a simple answer to it I am not sure but to explain I have a XML file I instantiate prefabs from with such things as Strings, Ints, Floats as the base variables for the prefab. My question is can I keep the XML with the base variables untouched and have a save file separate from the XML in a Binary Format that loads the players saved variables back over the top of the base variables set by the XML? also is this good Practice or is there a better way Cheers.