Yeh that's going to be a bit tougher because the image is massive.
And when you split the image you only split in 2 not 6.
If you want 2 that's fine.
So with 2 - you'd then fit the image to the frame to the width.
You need to CUT the image - and then select the Text Tool - place your cursor in a Text Frame as if you're going to Type then use Paste.
This puts the image in a text frame which makes it an anchored object and flows with the text.
You'll then need to make sure both images are the same scale. And then manually adjust the the position of the graphics within the frame to align them to the top and bottom.
But to get the image to flow between text frames - the text frames need to be Threaded - and the images have to be anchored so they move like text does.