Perhaps you've already discovered the 20 years of playable history that congeal together to form the Crusader Kings II demo? It appears to have marched onto the internet during the weekend, a time when I am traditionally to be found scrutinising medieval maps of Europe. This weekend I decided to be trapped in a cabin in the middle of the woods during a night of heavy snow instead, so I hadn't spotted the demo until now. Download it here.
A choice of four leaders and twenty years of history to play with should be enough to tide you over until the game comes out on Valentine's Day, at which point you can take a laptop to a fancy restaurant and conquer Scandinavia together by candlelight.
You can read about my experiences with the beta here.