Yep, them panties are pretty roomy. I ended up buying a 5 pair set from Ackermans. I also bought the small size, as their bums are just so small once the nappy is off.
That way they are not too expensive, and you do not feel mortally wounded when something happens and you have to throw them away.
Some days and in some circumstances, it is easier just to throw the dirty pantie away rather than facing getting what ever is on it off it.