No Diaper and pee while sleeping -Not a big problem just do laundry. No diaper and poop in sleep - disaster and big messy clean up. No diaper and poo and pee while sleeping - worst of all outcomes.
Tape on a diaper before bed and as long as its a good one I can relax and not worry -maybe the change in the morning will be routine if just wet, or complex if poop is involved but either way I'll cope.