I think considering the time of year, you could at least do a partial repot...still plenty of summer left down there in Virginia for recovery.
I wouldn't take the current rootball and just plunk it down into a larger pot surrounded by very free-draining mix. I'd want to loosen up the current rootball first. Use a root hook or whatever tool you prefer to tease out the sides and bottom, and then aerate the rest of the root mass by poking holes with a chopstick, old screwdriver, etc to increase the drainage. Backfill with new soil.
FWIW, remember I bought 2 of the "Fred" ficuses a couple of years ago. Both were incredibly rootbound. I did a full repot on one and the other, I just unpotted, teased out the sides/bottom and reduced a bit, aerated the rest, and put it back in the same container with some new soil. It is still doing well, I haven't gotten around to the full repot yet. Root mass is very dense.
Possibly some of the leaf yellowing/dropping is related to the shipping process.