an interesting phrase is working as little as possible. This is an organizational issue more so than a motivation one. I work remote and am assigned all my work on a monday that is due by the end of the day friday. If I don't do it, there will be questions asked. Because of the way our company is organized, working as little as possible means working exactly as expected.
You have an interesting setup, where both tasks and time allocation are given to you ("implement X, you have 5 days"). Do you have any say in how long something is supposed to take?