If you are planning to bring your child up bi-lingual in the languages you speak then one of you should talk to your LO in German only and the other one in English only. It doesn't matter that you speak to your DH in English you just need to be strict in speaking your dedicated language with your child. I know it is hard, even harder when you are with other mums who don't really understand but at the end of your day, it is what you want for your child that's why it is important to stick with it. We are using the same method at home and so far it is working fine.
In regards to Kindergarden/School, that is a tricky one and I guess only you can take the decision. The German school seems quite German and English is not taught by a native English speaker which was an issue for us.
There are also other options to incorporate German. TCG in the Green Community is a bi-lingual Kindergarden. And the Greenfield Community School offers German as part of the Curriculum. The likes of DIA & Raffles also offer German but this comes as an additional cost and is organized by a parent initiative.
Good luck with whatever you decide.
Is anyone able to give feedback? We are thinking of signing our LO up for kindergarden there. We are trying to teach her english and german... but it is proving to be harder than we thought. I keep slipping over to speaking english with her, even when we are alone. :/