All of your Home columns will be larger!
Works only for https://tweetdeck.twitter.com/, not the apps. (Maybe Chrome app support next?)

If you want to custom the width, check this one: http://freestyler.ws/style/122498/tweetdeck-change-home-column-width

The columns width will not change with the TweetDeck options. You can modify this userstyle locally with your desired width if you want. (Change the "500px" with what you want.)

BONUS! I've done some fixes when using others userstyles/extensions. You may check out if you see something interesting to copy here: https://github.com/mkody/tdeck-us-fix