How long can I leave my yeast cake in my carboy? I transferred the beer to a keg pushing with CO2 so there is no O2 present. The carboy is now in my fridge awaiting it its next victim. Hopefully a BW!!!
I suspect you could "probably" leave it a week or 2 and it would be ok, give it a smell type approach.
But if your not intending on brewing with it like, tomorrow? then why not wash it a little and make a new starter.