How to override a device tree and move a node?

Question

I have a dts file that includes a rather generic dtsi file but needs to remove a node from one subtree and move it to another. If I simply go in the base dts and add the node to where it should be, the resulting dtb has both the original as well as the new.

original dtsi:

a {
    b1 {
    };
    b2 {
       c {};
    };   
};

override:

#include "original.dtsi"

a {
    b1{
        c{};
    };
};

The problem is that I then have a 'c' node in both 'b1' and 'b2'