Our outdoor wedding's rain plan is a tent. What should we do about lightning?

When I asked where our seventy guests would go during a thunderstorm, the venue sent the same photograph of its reception tent. "We can put all the sides down," the manager said.

We're planning a US outdoor wedding, still four months away. We booked for the setting and have paid for invitations showing the garden. My partner thinks I'm trying to move the whole wedding because of weather that hasn't happened.

I'm not trying to predict the day. The [National Weather Service says tents and open-sided picnic shelters aren't safe lightning shelter](https://www.weather.gov/safety/lightning-outdoors). The venue hasn't yet identified a suitable building or a workable shelter plan for everyone. Most guests are arriving by coach, so we can't just assume they will have cars there.

A nearby hall has offered us the date for $850 and needs an answer next week. We'd have to check its capacity and arrangements before booking. It would mean changing the wedding we pictured, but I don't want our only plan to be hoping it stays fine.

How would you give the current venue a fair chance to answer without letting the alternative disappear while it keeps discussing rain?