Make your organizer 1-26mm wider. 1-10mm is €22.50, 11-26mm is €30.00
(PS. this is calculated on a closed binder, so 1mm wider means 1mm on each side = 2mm in total on an open binder.) You also have the option to add 2 extra slip pockets to accommodate the extra width in your planner (= €35.00 extra).