I see two outcomes: either UK Tories from 1993 onward, where open civil war erupts and they run out the clock, or the Canadian Liberals in the mid-2000s: fatally damaged but only lose narrowly when the votes are tallied with the real implosion coming later.
Or Aus '93?
The rule is that you get one waiver post-coup before a long stay in opposition. Oz 1993, UK 1992, Canada 2004. That waiver was used last year. Among the many differences, Keating probably didn't have openly bubbling intraparty dissent to the point of detailed coup rumors.