I agree with ThawkMike and others... getting a new trans is not a big deal, as long as they get it done _very quickly_. It should be back to you, all buttoned up in no more than a week's time. Removal and reinstall is a one day job. Shipping a brand new trans may take a couple of days.
The transmissions, with everything else left stock, are tough and have a very low failure rate, so your new one should be good and you can enjoy your new vehicle in no time, for a long time.
'18 Billet Silver Trackhawk
'02 Lingenfelter Twin Turbo Z06
'11 Corvette ZR1
'14 Audi SQ5