Very interesting question and I think Manchester City management will not sack Guardiola even if Manchester City crashes out of the EPL given the merits to the club.
But now I don't think Guardiola is to blame for City's defeats, but rather injuries to a huge number of City players and partly City's not very active transfer policy this season. Most of City's victories have come from players that Guardiola bought a few years ago.
Besides, Guardiola's contract is about to expire and maybe he himself wants to leave City for some Saudi clubs to make money.
Pep did many things for Manchester City, helped them to win many titles so it's possible that Manchester City will respect him and allow him to complete a season, even it is bad, before they separate with each other at the season ending or in the summer transfer season.
Pep Guardiola doesn't want to stay at a same club for too long and Manchester City is where he stays longest so far. Soon the party will end and he already won Champions League with them, so it's not too serious if he leaves. I believe that Manchester City will have bigger problem if Pep leaves the club, because Pep can find many big clubs in Europe to work with, if he want.
Guardiola will definitely finish the season at City and in general, City's chances for the championship are still huge and apart from Liverpool the other teams are not showing their best game either. Aston Villa are failing so far, Tottenham too, Arsenal are also not showing their best game and only Chesley and Liverpool are showing better game than last season and if Liverpool don't lose a lot and keep gaining points then Liverpool will probably become champions, but there is still a lot of time till the end of the season, so City still have chances.
Besides, it is not clear where Guardiola should leave City, because he has made City one of the strongest clubs of our time.