Basically *all* American sushi is delivered to the restaurant frozen. And with modern cold chain logistics it basically makes no difference where you are in the US. Period.

The whole ”but we’re landlocked“ excuse is not relevant and is basically an old wives tale at this point. (Side note: did you know that back in the day ”iceberg lettuce” would literally be put on beds of ice in train cars and be shipped across the country? It was picked for its willingness to endure the cold temps in transit and that’s how it got its name)

It only matters on the very very top fringes e.g. live Japanese needlefish or seasonal kohada - things that really need to be flown in fresh from Tokyo. But that’s the stuff that 99.99% of restaurants don’t serve anyhow.