If you have Muji in your country, This case is awesome:
http://www.muji.com.sg/store/4549738308157.html?cl=no_color_code_4549738308157
It fits 12.9" iPad Pro with smart keyboard + thin case (e.g. Coverbuddy) perfectly, with some room for cables, A4 sized documents and apple pencil.
It's very thin, has carry handle that you can easily tuck in when not in use and provides enough padding when put inside your bag. On the other hand, It's definitely not shock proof and also not waterproof so it's meant to protect your ipad against scratches and light bumps.
EDIT: Forgot to mention but it also looks much better in person
http://www.muji.com.sg/store/4549738308157.html?cl=no_color_code_4549738308157
It fits 12.9" iPad Pro with smart keyboard + thin case (e.g. Coverbuddy) perfectly, with some room for cables, A4 sized documents and apple pencil.
It's very thin, has carry handle that you can easily tuck in when not in use and provides enough padding when put inside your bag. On the other hand, It's definitely not shock proof and also not waterproof so it's meant to protect your ipad against scratches and light bumps.
EDIT: Forgot to mention but it also looks much better in person