The other thing about HO is it doesn't cover any property that is outside your home. So, if someone breaks into your home and steals your cards, you can collect, however if you bring your cards to an event and they get stolen, they were outside your home and not covered.
This is 100% not true. I have never seen policy language that did not cover contents that were outside of the house and I've been in the industry handling claims and selling policies since 1998. I've handled claims for people with luggage stolen in Europe and there is definitely coverage. Contents coverage is typically world-wide except for another residence premise.
Best thing to do though is talk to your personal agent. Some states may have oddities I'm not aware of. And if you have an 'in the house only' policy, get that changed.