I love those potato skins as well - I think you should be OK with them - they are kept pretty hot. just don't eat anything that is luke warm - it's got to either have come from the fridge or be nice and hot.

Of course, if you regularly eat lots of things that are likely to contain listeria, you probably already have some immunity to it - but who wants to risk it?? The consequences of listeria in pregnancy can be pretty serious.