Running One-offs when you are down players one week

Every once in a while you have a few missing players one week, and the past few times we have decided to run one off sessions where I (the DM) just kind of make it up on the fly with no real preparation. I have also tried playing Lasers and Feelings, or the more germane Scrolls and Swords, but I was wondering if anyone has any good ideas for spicing up our one-off life, or maybe a better idea for when we have players missing. My campaign has taken a turn towards the more intricate and political with lots of decisions that the entire party really should be present for so I generally hesitate to try to press on when we are down players.

Any thoughts would be greatly appreciated.