Another neighbour in our complex of three blocks of flats will be moving in to their renovated flat soon, and so far they've put no more than their winter tyres in their cellar space. I finally got round to calling him to ask if I could rent the space, and he gave me permission to use it for the summer months! (This is a different space from the one I mentioned earlier. That guy's space is still empty and locked - he hasn't put anything in there as long as we can remember!)
It'll now be much easier for me to carry Beaatrice downstairs half a flight, through the cellar doors and straight into that almost empty space. It also frees up the balcony for us to use as normal during the summer months, which my dear lady is pleased about!