Advice on steam bending

Hi everyone,

I need to bend some oak for a project. I've done it before but it was a long time ago...

Two questions :

1. my plan is to bend a 40x70 mm (1,5" x 2,75") section of oak to a 500mm (20") internal radius, is that realistic?

2. do I have to steam the whole piece or can I build a smaller steam box to only accept the end that needs to be bent?

Thanks in advance for any help!

Edit: added measurements in inches for universal convenience