1 free dodge a week?

So I got done with a long day of work and school, so I jump into a ranked game. I have someone lock in support. My first thought is maybe she is trading with the top laner. They pick kayle, which is another top laner. I'm last pick, and decide to dodge because i don't want to lose 20lp (roughly) just because of champ select. My first thought was one free dodge a day, but i feel like that would be abused. I think a free dodge a week should be enough to avoid most trolls, and should just be a standard since dynamic que is stupid.