Before new carpet, we had floorboards covered, mostly, by a couple of cheap Ikea runners. This was not optimal for the Roomba, as it had a tendency to trip up at the edges of the runners, and thus the hall and the landing had to be done in stages, with strategic anchoring of corners with umbrella stands and kitchen stools and so forth.
But now I can set the Roomba going downstairs, put the guardian in the kitchen doorway, and he can zoom about the living room and hall with gay abandon, and then put himself to sleep. *Good* Roomba.
Similar goodness will happen upstairs, when he can do the hall and bathroom together.
It’s when it comes up the stairs by itself that you need to start worrying…
I never really came to terms with Daleks being able to levitate. If the Roomba starts, I’m off to the funny farm.