I am using Trello to manage work tasks. Each task has its own card. I've assigned due dates to each card, but I'd also like to indicate how long each task is estimated to take. Right now I am using labels to do this (one color means less than an hour, another color means 1-2 hours, another color means 2-3 hours, and so on), but this isn't as visually obvious as I'd like.
Ideally, I'd like to be able to change the height of each card according to its task duration: a task lasting less than an hour would be the default height, a 1-2-hour task would be bigger, and so on.
Is there any kind of power-up or other Trello feature that would allow me to correlate task duration with card size? If not, what other techniques do people use for visualizing how long a task will take?