Make Teemo's invisibility a charged move

I play a lot of teemo and have been watching the rework that's been going on for a while. I'm excited about it, but I feel like the new invisibility E is a bit... boring. Moving around while invisible is great and really adds some depth to it, but having to wait 2 seconds and use mana & long cooldown with the risk someone is going to see you go invisible anyways? ... Eh...

Here's my suggestion, make it charged (0- 1.5 sec). The longer you charge, the larger the area teemo can move in. Letting go starts a .5 sec channel or whatever to actually turn invisible. Think of it as "Setting up the area" for Guerilla warfare. The more time to setup, the more manueverability teemo has.

It rewards teemo for having good vision and being able to stop channeling and go invisible sooner if someone is coming, and rewards teemo if he gets a good setup/takes the time to do the full channel, IE more dynamic and interesting.

thoughts?