the codes will be different for the stereo/car
I have a 1999 bravo with no red key its just been in for repairs for 2 weeks (front end struck by idiot at work) I know for a fact the batt was removed for 2 days but my original blue key and clone still work ...
I would say you may never need it so not to worry
But keep in mind there are things you can do other than go to Fiat if the unthinkable happens and you become stuck
search is your friend, there have been many threads on this subject
Tim