Don't fall into the trap of believing all dragon's must behave the way you run themThat is irrelevant. It doesn't matter if it's one dragon against one player, or one dragon against a whole party.
When I run a dragon encounter, that dragon will try to kill the player(s), and it will be a fight to the death. The dragon doesn't offer an ultimatum for the player(s) to escape with their life when they're losing... but maybe I should, because it is a pretty cool idea, and fitting of an intelligent and cruel creature like a dragon.
Fights in D&D don't always have to be fair. Sometimes the CR of a monster will not be a fair challenge for the players, like with a dragon. A fight with a dragon should be deadly. The game isn't called Dungeons and Dragons for nothing.