@Laura2592 A friend who hosts in Canada got a booking and when she saw their photo after it was confirmed, and they were both quite obese, she knew they would never fit in the small shower stall in her attached studio.
She happened to have another issue she was having to notify guests about, which was public works digging up the street in front of her house. So without mentioning their weight, but just letting them know that the bathroom and shower stall were quite small, and asking if they had read that part of her ad, as well as making the construction project sound more disruptive than it actually was (it was noisy in the living room of the suite, but not in the bedroom, and wasn't going on every day), she really tried to get them to cancel, with full refund.
Oh no, they still wanted to keep the booking. So they arrived, red-faced and looking like they were about to have coronaries, having had to park a block away and shlep their luggage due to the construction, came in, took one look at the bathroom and shower, and wanted to cancel. My friend was really irritated, as she foresaw that would happen, but kept her cool and still offered a full refund just to get rid of them quickly.