IB in one year

I come from the German system, which is quite demanding. Last September I decided to do my A Levels instead and have been extremely bored by the little amount of work I have to do. I'm getting As in both mocks and official examinations and need a new challenge in life.

Would it be possible to complete the IB Diploma Programme in one year, considering that I wouldn't have to study for my HL subjects if I am already taking them as my A Levels?
I would only have to focus on my SL subjects and TOK/EE/CAS.

Thanks