Use a table?
There is always a solution!
With a proper layout design, this could be done in ... 1 click [2 regex] using the inevitable Multi-Find/Change of our friend Martinho da Gloria!
Fichier INDD [ID CC 2014]: Dropbox - FA-7762264.indd.zip
Thanks all for your suggestions.
Tables could be the simplest solution. Obi-Wan solutions seems to be the closest to what I want to achieve but I think it goes a step too far. To make things clear, here's what I would like to do :
Red arrows indicate where I would like to "Image Break"
Text is pushed after images like it would with a "Frame Break".