MK3 Transmission Control Module failure - Can I continue to drive?

Hello all,

I have owned a 2012 5 door Focus since 2012 and so far have avoided any MAJOR transmission issues until yesterday.  Upon starting my car yesterday morning a warning message popped up alerting me to transmission error, service now.  Symptoms include jerking shifting and not shifting past 3rd or 4th gear.  I was able to get my Focus in to the local dealership early in the morning and received a call back from them a few hours later stating the Transmission Control Module (TCM) is bad.  They then told me that it is covered under the warranty that Ford extended (car is only 53k miles) but that the replacement TCM is on back order with no ETA.  I was then told I can pick up my car and continue to drive it until 'it gets worse' at which point the dealership would put me in a loaner.  

When I inquired if driving it with a  bad TCM and pushing 5k RPMs in lower gear settings will damage my car further I was told no.  

When I inquired what getting worse is, I was told either the car will fail to start or I wont be able to shift past 1st or 2nd gear. 

Is what I am being told by the dealership correct?  It seems to my non mechanical brain that driving with a bad TCM can/will further damage the transmission of items not under warranty.  It also seems dangerous if the car has transmission problems while driving down the highway.

I did not buy the car from this dealership but is the loaner car they mentioned they would put me in when my car 'got worse' a courtesy of the dealership or something that would be reimbursed to them by Ford since there is no ETA on the replacement?