After nearly six years of ownership, I discovered it is very easy to remove the lower rear seat cushions on a 2020 110 SE with five seats. Mine has the split 40:20:40 rear bench and is not heated, so there are no cables to disconnect. There are only four Torx T40 bolts - two for the single section and two for the double section. Remove those and the lower cushions lift straight out. Here's a photo after removal.


Seat bolts

It frees up more storage space in the rear footwell. I also bought these , which fit perfectly and make it much more comfortable when sleeping in the rear of the vehicle. They fold up and store neatly under the front seats.


Inflatable cushion