And then klik said that we should have checked out the wares of the Atrium, where we got our desk chairs from a few years back. They specialise in 'ecological' furniture, which means it's a lot of solid wood. And that fits with the dining table, so it's certainly an option we should look at.
So we browsed through the site separately, and at the same time we saw the q_box. It's a stackable box, with optional drawers and even a wine rack. It's made of the scrap wood that's left when they make the big tables or chairs: lovely oiled solid wood (just like the dining table...).
The flexibility and the looks appealed to us, so we decided to check it out.
Within 20 minutes we had ordered 10 of the boxes, with an assortment of drawers, extra planks and a wine rack -- it just fits us and our house.