Narwal Freo S

It auto-empties into a 3.5 L bag, so you go weeks between swaps, but the mop is rinsed and the water tank filled by hand.

The robot is 3.9 inches tall, so it slides under most sofas and cabinets, though very low furniture may be tight.

It clears obstacles up to 20 mm, so it handles standard door sills but may stop at taller thresholds.

Yes. It supports no-go zones and stores maps for up to 4 levels, so you can fence off rooms across floors.