Electric roller shutters cost so much money, then maybe have normal ones installed and just insert the electric shaft yourself. You can buy them everywhere for 50-100 euros. Including the switch, I think you are at a maximum of 100 euros.
... don't forget, you also need power there, so just putting in the electric shaft is unfortunately not enough...
I am just thinking about what else we need to pay attention to... We will not make a third bathroom either and in the utility room, for example, only "standard" tiles will be installed, the cheapest and most durable. However, we are weighing whether this could be retrofitted later. With the chimney for the perhaps desired fireplace later on, it will be more difficult, but everything is possible...