Absolutely concur that you should take it to a large, corporate-owned location, and preferably between 9a-4p.
I say this because the best/nicest/highest up management usually works during this time.
Be honest with that person about your emergency situation. They can keep your existing rate plan and take the car back, if they want to.
They certainly will take the car back either way - if the option is between taking their asset in a different location or possibly not getting it back, they’ll always take the former.
If the person returning your vehicle (don’t let them close you out in a return lane, you will have to ask for the Return Manager, or go to the counter, to complete) doesn’t agree to keep your rate the same, you can ask them to estimate how much it will cost to return there, prior to actually doing it and closing the contract and charging your card.