Jeff, you shouldn´t worry bout the viability if the culture was kept at the safe below -20 degrees during storage.
SACCO usually "overdose" the amount of bacteria in the packets, so that even on the expiry date the user will have a cell count identical to what is stated on the information sheet.
And even if there should be a small percentage drop in bacteria activity after that overdue month I guess no one will be able to tell the difference unless they bring in the big microscope. After all the bacteria don´t just pop off from one day to the other just because we lable them to do so
Half a package would have done the job too, providing that you´d used the remaining half within a month or so.
Do you intend to give the sausages a light smoking at some point?
Not that I think it will chase the flies away but it may add some wellcome bacterial protection to the surface...